upload apache

JIRA: BOTTLENECK-10

Change-Id: I67eae31de6dc824097dfa56ab454ba36fdd23a2c
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>

1 files changed, 1495 insertions, 0 deletions

diff --git a/rubbos/app/apache2/include/apr_buckets.h b/rubbos/app/apache2/include/apr_buckets.h
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+/* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
+ * applicable.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @file apr_buckets.h
+ * @brief APR-UTIL Buckets/Bucket Brigades
+ */
+
+#ifndef APR_BUCKETS_H
+#define APR_BUCKETS_H
+
+#if defined(APR_BUCKET_DEBUG) && !defined(APR_RING_DEBUG)
+#define APR_RING_DEBUG
+#endif
+
+#include "apu.h"
+#include "apr_network_io.h"
+#include "apr_file_io.h"
+#include "apr_general.h"
+#include "apr_mmap.h"
+#include "apr_errno.h"
+#include "apr_ring.h"
+#include "apr.h"
+#if APR_HAVE_SYS_UIO_H
+#include <sys/uio.h>	/* for struct iovec */
+#endif
+#if APR_HAVE_STDARG_H
+#include <stdarg.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @defgroup APR_Util_Bucket_Brigades Bucket Brigades
+ * @ingroup APR_Util
+ * @{ 
+ */
+
+/** default bucket buffer size - 8KB minus room for memory allocator headers */
+#define APR_BUCKET_BUFF_SIZE 8000
+
+/** Determines how a bucket or brigade should be read */
+typedef enum {
+    APR_BLOCK_READ,   /**< block until data becomes available */
+    APR_NONBLOCK_READ /**< return immediately if no data is available */
+} apr_read_type_e;
+
+/**
+ * The one-sentence buzzword-laden overview: Bucket brigades represent
+ * a complex data stream that can be passed through a layered IO
+ * system without unnecessary copying. A longer overview follows...
+ *
+ * A bucket brigade is a doubly linked list (ring) of buckets, so we
+ * aren't limited to inserting at the front and removing at the end.
+ * Buckets are only passed around as members of a brigade, although
+ * singleton buckets can occur for short periods of time.
+ *
+ * Buckets are data stores of various types. They can refer to data in
+ * memory, or part of a file or mmap area, or the output of a process,
+ * etc. Buckets also have some type-dependent accessor functions:
+ * read, split, copy, setaside, and destroy.
+ *
+ * read returns the address and size of the data in the bucket. If the
+ * data isn't in memory then it is read in and the bucket changes type
+ * so that it can refer to the new location of the data. If all the
+ * data doesn't fit in the bucket then a new bucket is inserted into
+ * the brigade to hold the rest of it.
+ *
+ * split divides the data in a bucket into two regions. After a split
+ * the original bucket refers to the first part of the data and a new
+ * bucket inserted into the brigade after the original bucket refers
+ * to the second part of the data. Reference counts are maintained as
+ * necessary.
+ *
+ * setaside ensures that the data in the bucket has a long enough
+ * lifetime. Sometimes it is convenient to create a bucket referring
+ * to data on the stack in the expectation that it will be consumed
+ * (output to the network) before the stack is unwound. If that
+ * expectation turns out not to be valid, the setaside function is
+ * called to move the data somewhere safer.
+ *
+ * copy makes a duplicate of the bucket structure as long as it's
+ * possible to have multiple references to a single copy of the
+ * data itself.  Not all bucket types can be copied.
+ *
+ * destroy maintains the reference counts on the resources used by a
+ * bucket and frees them if necessary.
+ *
+ * Note: all of the above functions have wrapper macros (apr_bucket_read(),
+ * apr_bucket_destroy(), etc), and those macros should be used rather
+ * than using the function pointers directly.
+ *
+ * To write a bucket brigade, they are first made into an iovec, so that we
+ * don't write too little data at one time.  Currently we ignore compacting the
+ * buckets into as few buckets as possible, but if we really want good
+ * performance, then we need to compact the buckets before we convert to an
+ * iovec, or possibly while we are converting to an iovec.
+ */
+
+/*
+ * Forward declaration of the main types.
+ */
+
+/** @see apr_bucket_brigade */
+typedef struct apr_bucket_brigade apr_bucket_brigade;
+/** @see apr_bucket */
+typedef struct apr_bucket apr_bucket;
+/** @see apr_bucket_alloc_t */
+typedef struct apr_bucket_alloc_t apr_bucket_alloc_t;
+
+/** @see apr_bucket_type_t */
+typedef struct apr_bucket_type_t apr_bucket_type_t;
+
+/**
+ * Basic bucket type
+ */
+struct apr_bucket_type_t {
+    /**
+     * The name of the bucket type
+     */
+    const char *name;
+    /** 
+     * The number of functions this bucket understands.  Can not be less than
+     * five.
+     */
+    int num_func;
+    /**
+     * Whether the bucket contains metadata (ie, information that
+     * describes the regular contents of the brigade).  The metadata
+     * is not returned by apr_bucket_read() and is not indicated by
+     * the ->length of the apr_bucket itself.  In other words, an
+     * empty bucket is safe to arbitrarily remove if and only if it
+     * contains no metadata.  In this sense, "data" is just raw bytes
+     * that are the "content" of the brigade and "metadata" describes
+     * that data but is not a proper part of it.
+     */
+    enum {
+        /** This bucket type represents actual data to send to the client. */
+        APR_BUCKET_DATA = 0,
+        /** This bucket type represents metadata. */
+        APR_BUCKET_METADATA = 1
+    } is_metadata;
+    /**
+     * Free the private data and any resources used by the bucket (if they
+     *  aren't shared with another bucket).  This function is required to be
+     *  implemented for all bucket types, though it might be a no-op on some
+     *  of them (namely ones that never allocate any private data structures).
+     * @param data The private data pointer from the bucket to be destroyed
+     */
+    void (*destroy)(void *data);
+
+    /**
+     * Read the data from the bucket. This is required to be implemented
+     *  for all bucket types.
+     * @param b The bucket to read from
+     * @param str A place to store the data read.  Allocation should only be
+     *            done if absolutely necessary. 
+     * @param len The amount of data read.
+     * @param block Should this read function block if there is more data that
+     *              cannot be read immediately.
+     */
+    apr_status_t (*read)(apr_bucket *b, const char **str, apr_size_t *len, 
+                         apr_read_type_e block);
+    
+    /**
+     * Make it possible to set aside the data for at least as long as the
+     *  given pool. Buckets containing data that could potentially die before
+     *  this pool (e.g. the data resides on the stack, in a child pool of
+     *  the given pool, or in a disjoint pool) must somehow copy, shift, or
+     *  transform the data to have the proper lifetime.
+     * @param e The bucket to convert
+     * @remark Some bucket types contain data that will always outlive the
+     *         bucket itself. For example no data (EOS and FLUSH), or the data
+     *         resides in global, constant memory (IMMORTAL), or the data is on
+     *      the heap (HEAP). For these buckets, apr_bucket_setaside_noop can
+     *      be used.
+     */
+    apr_status_t (*setaside)(apr_bucket *e, apr_pool_t *pool);
+
+    /**
+     * Split one bucket in two at the specified position by duplicating
+     *  the bucket structure (not the data) and modifying any necessary
+     *  start/end/offset information.  If it's not possible to do this
+     *  for the bucket type (perhaps the length of the data is indeterminate,
+     *  as with pipe and socket buckets), then APR_ENOTIMPL is returned.
+     * @param e The bucket to split
+     * @param point The offset of the first byte in the new bucket
+     */
+    apr_status_t (*split)(apr_bucket *e, apr_size_t point);
+
+    /**
+     * Copy the bucket structure (not the data), assuming that this is
+     *  possible for the bucket type. If it's not, APR_ENOTIMPL is returned.
+     * @param e The bucket to copy
+     * @param c Returns a pointer to the new bucket
+     */
+    apr_status_t (*copy)(apr_bucket *e, apr_bucket **c);
+
+};
+
+/**
+ * apr_bucket structures are allocated on the malloc() heap and
+ * their lifetime is controlled by the parent apr_bucket_brigade
+ * structure. Buckets can move from one brigade to another e.g. by
+ * calling APR_BRIGADE_CONCAT(). In general the data in a bucket has
+ * the same lifetime as the bucket and is freed when the bucket is
+ * destroyed; if the data is shared by more than one bucket (e.g.
+ * after a split) the data is freed when the last bucket goes away.
+ */
+struct apr_bucket {
+    /** Links to the rest of the brigade */
+    APR_RING_ENTRY(apr_bucket) link;
+    /** The type of bucket.  */
+    const apr_bucket_type_t *type;
+    /** The length of the data in the bucket.  This could have been implemented
+     *  with a function, but this is an optimization, because the most
+     *  common thing to do will be to get the length.  If the length is unknown,
+     *  the value of this field will be (apr_size_t)(-1).
+     */
+    apr_size_t length;
+    /** The start of the data in the bucket relative to the private base
+     *  pointer.  The vast majority of bucket types allow a fixed block of
+     *  data to be referenced by multiple buckets, each bucket pointing to
+     *  a different segment of the data.  That segment starts at base+start
+     *  and ends at base+start+length.  
+     *  If the length == (apr_size_t)(-1), then start == -1.
+     */
+    apr_off_t start;
+    /** type-dependent data hangs off this pointer */
+    void *data;	
+    /**
+     * Pointer to function used to free the bucket. This function should
+     * always be defined and it should be consistent with the memory
+     * function used to allocate the bucket. For example, if malloc() is 
+     * used to allocate the bucket, this pointer should point to free().
+     * @param e Pointer to the bucket being freed
+     */
+    void (*free)(void *e);
+    /** The freelist from which this bucket was allocated */
+    apr_bucket_alloc_t *list;
+};
+
+/** A list of buckets */
+struct apr_bucket_brigade {
+    /** The pool to associate the brigade with.  The data is not allocated out
+     *  of the pool, but a cleanup is registered with this pool.  If the 
+     *  brigade is destroyed by some mechanism other than pool destruction,
+     *  the destroying function is responsible for killing the cleanup.
+     */
+    apr_pool_t *p;
+    /** The buckets in the brigade are on this list. */
+    /*
+     * The apr_bucket_list structure doesn't actually need a name tag
+     * because it has no existence independent of struct apr_bucket_brigade;
+     * the ring macros are designed so that you can leave the name tag
+     * argument empty in this situation but apparently the Windows compiler
+     * doesn't like that.
+     */
+    APR_RING_HEAD(apr_bucket_list, apr_bucket) list;
+    /** The freelist from which this bucket was allocated */
+    apr_bucket_alloc_t *bucket_alloc;
+};
+
+
+/**
+ * Function called when a brigade should be flushed
+ */
+typedef apr_status_t (*apr_brigade_flush)(apr_bucket_brigade *bb, void *ctx);
+
+/*
+ * define APR_BUCKET_DEBUG if you want your brigades to be checked for
+ * validity at every possible instant.  this will slow your code down
+ * substantially but is a very useful debugging tool.
+ */
+#ifdef APR_BUCKET_DEBUG
+
+#define APR_BRIGADE_CHECK_CONSISTENCY(b)				\
+        APR_RING_CHECK_CONSISTENCY(&(b)->list, apr_bucket, link)
+
+#define APR_BUCKET_CHECK_CONSISTENCY(e)					\
+        APR_RING_CHECK_ELEM_CONSISTENCY((e), apr_bucket, link)
+
+#else
+/**
+ * checks the ring pointers in a bucket brigade for consistency.  an
+ * abort() will be triggered if any inconsistencies are found.
+ *   note: this is a no-op unless APR_BUCKET_DEBUG is defined.
+ * @param b The brigade
+ */
+#define APR_BRIGADE_CHECK_CONSISTENCY(b)
+/**
+ * checks the brigade a bucket is in for ring consistency.  an
+ * abort() will be triggered if any inconsistencies are found.
+ *   note: this is a no-op unless APR_BUCKET_DEBUG is defined.
+ * @param e The bucket
+ */
+#define APR_BUCKET_CHECK_CONSISTENCY(e)
+#endif
+
+
+/**
+ * Wrappers around the RING macros to reduce the verbosity of the code
+ * that handles bucket brigades.
+ */
+/**
+ * The magic pointer value that indicates the head of the brigade
+ * @remark This is used to find the beginning and end of the brigade, eg:
+ * <pre>
+ *      while (e != APR_BRIGADE_SENTINEL(b)) {
+ *          ...
+ *          e = APR_BUCKET_NEXT(e);
+ *      }
+ * </pre>
+ * @param  b The brigade
+ * @return The magic pointer value
+ */
+#define APR_BRIGADE_SENTINEL(b)	APR_RING_SENTINEL(&(b)->list, apr_bucket, link)
+
+/**
+ * Determine if the bucket brigade is empty
+ * @param b The brigade to check
+ * @return true or false
+ */
+#define APR_BRIGADE_EMPTY(b)	APR_RING_EMPTY(&(b)->list, apr_bucket, link)
+
+/**
+ * Return the first bucket in a brigade
+ * @param b The brigade to query
+ * @return The first bucket in the brigade
+ */
+#define APR_BRIGADE_FIRST(b)	APR_RING_FIRST(&(b)->list)
+/**
+ * Return the last bucket in a brigade
+ * @param b The brigade to query
+ * @return The last bucket in the brigade
+ */
+#define APR_BRIGADE_LAST(b)	APR_RING_LAST(&(b)->list)
+
+/**
+ * Iterate through a bucket brigade
+ * @param e The current bucket
+ * @param b The brigade to iterate over
+ * @remark This is the same as either:
+ * <pre>
+ *	e = APR_BRIGADE_FIRST(b);
+ * 	while (e != APR_BRIGADE_SENTINEL(b)) {
+ *	    ...
+ * 	    e = APR_BUCKET_NEXT(e);
+ * 	}
+ *  OR
+ * 	for (e = APR_BRIGADE_FIRST(b);
+ *           e != APR_BRIGADE_SENTINEL(b);
+ *           e = APR_BUCKET_NEXT(e)) {
+ *	    ...
+ * 	}
+ * </pre>
+ * @warning Be aware that you cannot change the value of e within
+ * the foreach loop, nor can you destroy the bucket it points to.
+ * Modifying the prev and next pointers of the bucket is dangerous
+ * but can be done if you're careful.  If you change e's value or
+ * destroy the bucket it points to, then APR_BRIGADE_FOREACH
+ * will have no way to find out what bucket to use for its next
+ * iteration.  The reason for this can be seen by looking closely
+ * at the equivalent loops given in the tip above.  So, for example,
+ * if you are writing a loop that empties out a brigade one bucket
+ * at a time, APR_BRIGADE_FOREACH just won't work for you.  Do it
+ * by hand, like so:
+ * <pre>
+ *      while (!APR_BRIGADE_EMPTY(b)) {
+ *          e = APR_BRIGADE_FIRST(b);
+ *          ...
+ *          apr_bucket_delete(e);
+ *      }
+ * </pre>
+ * @deprecated This macro causes more headaches than it's worth.  Use
+ * one of the alternatives documented here instead; the clarity gained
+ * in what's really going on is well worth the extra line or two of code.
+ * This macro will be removed at some point in the future.
+ */
+#define APR_BRIGADE_FOREACH(e, b)					\
+	APR_RING_FOREACH((e), &(b)->list, apr_bucket, link)
+
+/**
+ * Insert a list of buckets at the front of a brigade
+ * @param b The brigade to add to
+ * @param e The first bucket in a list of buckets to insert
+ */
+#define APR_BRIGADE_INSERT_HEAD(b, e) do {				\
+	apr_bucket *ap__b = (e);                                        \
+	APR_RING_INSERT_HEAD(&(b)->list, ap__b, apr_bucket, link);	\
+        APR_BRIGADE_CHECK_CONSISTENCY((b));				\
+    } while (0)
+
+/**
+ * Insert a list of buckets at the end of a brigade
+ * @param b The brigade to add to
+ * @param e The first bucket in a list of buckets to insert
+ */
+#define APR_BRIGADE_INSERT_TAIL(b, e) do {				\
+	apr_bucket *ap__b = (e);					\
+	APR_RING_INSERT_TAIL(&(b)->list, ap__b, apr_bucket, link);	\
+        APR_BRIGADE_CHECK_CONSISTENCY((b));				\
+    } while (0)
+
+/**
+ * Concatenate brigade b onto the end of brigade a, leaving brigade b empty
+ * @param a The first brigade
+ * @param b The second brigade
+ */
+#define APR_BRIGADE_CONCAT(a, b) do {					\
+        APR_RING_CONCAT(&(a)->list, &(b)->list, apr_bucket, link);	\
+        APR_BRIGADE_CHECK_CONSISTENCY((a));				\
+    } while (0)
+
+/**
+ * Prepend brigade b onto the beginning of brigade a, leaving brigade b empty
+ * @param a The first brigade
+ * @param b The second brigade
+ */
+#define APR_BRIGADE_PREPEND(a, b) do {					\
+        APR_RING_PREPEND(&(a)->list, &(b)->list, apr_bucket, link);	\
+        APR_BRIGADE_CHECK_CONSISTENCY((a));				\
+    } while (0)
+
+/**
+ * Insert a list of buckets before a specified bucket
+ * @param a The bucket to insert before
+ * @param b The buckets to insert
+ */
+#define APR_BUCKET_INSERT_BEFORE(a, b) do {				\
+	apr_bucket *ap__a = (a), *ap__b = (b);				\
+	APR_RING_INSERT_BEFORE(ap__a, ap__b, link);			\
+        APR_BUCKET_CHECK_CONSISTENCY(ap__a);				\
+    } while (0)
+
+/**
+ * Insert a list of buckets after a specified bucket
+ * @param a The bucket to insert after
+ * @param b The buckets to insert
+ */
+#define APR_BUCKET_INSERT_AFTER(a, b) do {				\
+	apr_bucket *ap__a = (a), *ap__b = (b);				\
+	APR_RING_INSERT_AFTER(ap__a, ap__b, link);			\
+        APR_BUCKET_CHECK_CONSISTENCY(ap__a);				\
+    } while (0)
+
+/**
+ * Get the next bucket in the list
+ * @param e The current bucket
+ * @return The next bucket
+ */
+#define APR_BUCKET_NEXT(e)	APR_RING_NEXT((e), link)
+/**
+ * Get the previous bucket in the list
+ * @param e The current bucket
+ * @return The previous bucket
+ */
+#define APR_BUCKET_PREV(e)	APR_RING_PREV((e), link)
+
+/**
+ * Remove a bucket from its bucket brigade
+ * @param e The bucket to remove
+ */
+#define APR_BUCKET_REMOVE(e)	APR_RING_REMOVE((e), link)
+
+/**
+ * Initialize a new bucket's prev/next pointers
+ * @param e The bucket to initialize
+ */
+#define APR_BUCKET_INIT(e)	APR_RING_ELEM_INIT((e), link)
+
+/**
+ * Determine if a bucket contains metadata.  An empty bucket is
+ * safe to arbitrarily remove if and only if this is false.
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_METADATA(e)    ((e)->type->is_metadata)
+
+/**
+ * Determine if a bucket is a FLUSH bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_FLUSH(e)       ((e)->type == &apr_bucket_type_flush)
+/**
+ * Determine if a bucket is an EOS bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_EOS(e)         ((e)->type == &apr_bucket_type_eos)
+/**
+ * Determine if a bucket is a FILE bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_FILE(e)        ((e)->type == &apr_bucket_type_file)
+/**
+ * Determine if a bucket is a PIPE bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_PIPE(e)        ((e)->type == &apr_bucket_type_pipe)
+/**
+ * Determine if a bucket is a SOCKET bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_SOCKET(e)      ((e)->type == &apr_bucket_type_socket)
+/**
+ * Determine if a bucket is a HEAP bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_HEAP(e)        ((e)->type == &apr_bucket_type_heap)
+/**
+ * Determine if a bucket is a TRANSIENT bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_TRANSIENT(e)   ((e)->type == &apr_bucket_type_transient)
+/**
+ * Determine if a bucket is a IMMORTAL bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_IMMORTAL(e)    ((e)->type == &apr_bucket_type_immortal)
+#if APR_HAS_MMAP
+/**
+ * Determine if a bucket is a MMAP bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_MMAP(e)        ((e)->type == &apr_bucket_type_mmap)
+#endif
+/**
+ * Determine if a bucket is a POOL bucket
+ * @param e The bucket to inspect
+ * @return true or false
+ */
+#define APR_BUCKET_IS_POOL(e)        ((e)->type == &apr_bucket_type_pool)
+
+/*
+ * General-purpose reference counting for the various bucket types.
+ *
+ * Any bucket type that keeps track of the resources it uses (i.e.
+ * most of them except for IMMORTAL, TRANSIENT, and EOS) needs to
+ * attach a reference count to the resource so that it can be freed
+ * when the last bucket that uses it goes away. Resource-sharing may
+ * occur because of bucket splits or buckets that refer to globally
+ * cached data. */
+
+/** @see apr_bucket_refcount */
+typedef struct apr_bucket_refcount apr_bucket_refcount;
+/**
+ * The structure used to manage the shared resource must start with an
+ * apr_bucket_refcount which is updated by the general-purpose refcount
+ * code. A pointer to the bucket-type-dependent private data structure
+ * can be cast to a pointer to an apr_bucket_refcount and vice versa.
+ */
+struct apr_bucket_refcount {
+    /** The number of references to this bucket */
+    int          refcount;
+};
+
+/*  *****  Reference-counted bucket types  *****  */
+
+/** @see apr_bucket_heap */
+typedef struct apr_bucket_heap apr_bucket_heap;
+/**
+ * A bucket referring to data allocated off the heap.
+ */
+struct apr_bucket_heap {
+    /** Number of buckets using this memory */
+    apr_bucket_refcount  refcount;
+    /** The start of the data actually allocated.  This should never be
+     * modified, it is only used to free the bucket.
+     */
+    char    *base;
+    /** how much memory was allocated */
+    apr_size_t  alloc_len;
+    /** function to use to delete the data */
+    void (*free_func)(void *data);
+};
+
+/** @see apr_bucket_pool */
+typedef struct apr_bucket_pool apr_bucket_pool;
+/**
+ * A bucket referring to data allocated from a pool
+ */
+struct apr_bucket_pool {
+    /** The pool bucket must be able to be easily morphed to a heap
+     * bucket if the pool gets cleaned up before all references are
+     * destroyed.  This apr_bucket_heap structure is populated automatically
+     * when the pool gets cleaned up, and subsequent calls to pool_read()
+     * will result in the apr_bucket in question being morphed into a
+     * regular heap bucket.  (To avoid having to do many extra refcount
+     * manipulations and b->data manipulations, the apr_bucket_pool
+     * struct actually *contains* the apr_bucket_heap struct that it
+     * will become as its first element; the two share their
+     * apr_bucket_refcount members.)
+     */
+    apr_bucket_heap  heap;
+    /** The block of data actually allocated from the pool.
+     * Segments of this block are referenced by adjusting
+     * the start and length of the apr_bucket accordingly.
+     * This will be NULL after the pool gets cleaned up.
+     */
+    const char *base;
+    /** The pool the data was allocated from.  When the pool
+     * is cleaned up, this gets set to NULL as an indicator
+     * to pool_read() that the data is now on the heap and
+     * so it should morph the bucket into a regular heap
+     * bucket before continuing.
+     */
+    apr_pool_t *pool;
+    /** The freelist this structure was allocated from, which is
+     * needed in the cleanup phase in order to allocate space on the heap
+     */
+    apr_bucket_alloc_t *list;
+};
+
+#if APR_HAS_MMAP
+/** @see apr_bucket_mmap */
+typedef struct apr_bucket_mmap apr_bucket_mmap;
+/**
+ * A bucket referring to an mmap()ed file
+ */
+struct apr_bucket_mmap {
+    /** Number of buckets using this memory */
+    apr_bucket_refcount  refcount;
+    /** The mmap this sub_bucket refers to */
+    apr_mmap_t *mmap;
+};
+#endif
+
+/** @see apr_bucket_file */
+typedef struct apr_bucket_file apr_bucket_file;
+/**
+ * A bucket referring to an file
+ */
+struct apr_bucket_file {
+    /** Number of buckets using this memory */
+    apr_bucket_refcount  refcount;
+    /** The file this bucket refers to */
+    apr_file_t *fd;
+    /** The pool into which any needed structures should
+     *  be created while reading from this file bucket */
+    apr_pool_t *readpool;
+#if APR_HAS_MMAP
+    /** Whether this bucket should be memory-mapped if
+     *  a caller tries to read from it */
+    int can_mmap;
+#endif /* APR_HAS_MMAP */
+};
+
+/** @see apr_bucket_structs */
+typedef union apr_bucket_structs apr_bucket_structs;
+/**
+ * A union of all bucket structures so we know what
+ * the max size is.
+ */
+union apr_bucket_structs {
+    apr_bucket      b;      /**< Bucket */
+    apr_bucket_heap heap;   /**< Heap */
+    apr_bucket_pool pool;   /**< Pool */
+#if APR_HAS_MMAP
+    apr_bucket_mmap mmap;   /**< MMap */
+#endif
+    apr_bucket_file file;   /**< File */
+};
+
+/**
+ * The amount that apr_bucket_alloc() should allocate in the common case.
+ * Note: this is twice as big as apr_bucket_structs to allow breathing
+ * room for third-party bucket types.
+ */
+#define APR_BUCKET_ALLOC_SIZE  APR_ALIGN_DEFAULT(2*sizeof(apr_bucket_structs))
+
+/*  *****  Bucket Brigade Functions  *****  */
+/**
+ * Create a new bucket brigade.  The bucket brigade is originally empty.
+ * @param p The pool to associate with the brigade.  Data is not allocated out
+ *          of the pool, but a cleanup is registered.
+ * @param list The bucket allocator to use
+ * @return The empty bucket brigade
+ */
+APU_DECLARE(apr_bucket_brigade *) apr_brigade_create(apr_pool_t *p,
+                                                     apr_bucket_alloc_t *list);
+
+/**
+ * destroy an entire bucket brigade.  This includes destroying all of the
+ * buckets within the bucket brigade's bucket list. 
+ * @param b The bucket brigade to destroy
+ */
+APU_DECLARE(apr_status_t) apr_brigade_destroy(apr_bucket_brigade *b);
+
+/**
+ * empty out an entire bucket brigade.  This includes destroying all of the
+ * buckets within the bucket brigade's bucket list.  This is similar to
+ * apr_brigade_destroy(), except that it does not deregister the brigade's
+ * pool cleanup function.
+ * @param data The bucket brigade to clean up
+ * @remark Generally, you should use apr_brigade_destroy().  This function
+ *         can be useful in situations where you have a single brigade that
+ *         you wish to reuse many times by destroying all of the buckets in
+ *         the brigade and putting new buckets into it later.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_cleanup(void *data);
+
+/**
+ * Split a bucket brigade into two, such that the given bucket is the
+ * first in the new bucket brigade. This function is useful when a
+ * filter wants to pass only the initial part of a brigade to the next
+ * filter.
+ * @param b The brigade to split
+ * @param e The first element of the new brigade
+ * @return The new brigade
+ */
+APU_DECLARE(apr_bucket_brigade *) apr_brigade_split(apr_bucket_brigade *b,
+                                                    apr_bucket *e);
+
+/**
+ * Partition a bucket brigade at a given offset (in bytes from the start of
+ * the brigade).  This is useful whenever a filter wants to use known ranges
+ * of bytes from the brigade; the ranges can even overlap.
+ * @param b The brigade to partition
+ * @param point The offset at which to partition the brigade
+ * @param after_point Returns a pointer to the first bucket after the partition
+ */
+APU_DECLARE(apr_status_t) apr_brigade_partition(apr_bucket_brigade *b,
+                                                apr_off_t point,
+                                                apr_bucket **after_point);
+
+#if APR_NOT_DONE_YET
+/**
+ * consume nbytes from beginning of b -- call apr_bucket_destroy as
+ * appropriate, and/or modify start on last element 
+ * @param b The brigade to consume data from
+ * @param nbytes The number of bytes to consume
+ */
+APU_DECLARE(void) apr_brigade_consume(apr_bucket_brigade *b,
+                                      apr_off_t nbytes);
+#endif
+
+/**
+ * Return the total length of the brigade.
+ * @param bb The brigade to compute the length of
+ * @param read_all Read unknown-length buckets to force a size
+ * @param length Returns the length of the brigade, or -1 if the brigade has
+ *               buckets of indeterminate length and read_all is 0.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_length(apr_bucket_brigade *bb,
+                                             int read_all,
+                                             apr_off_t *length);
+
+/**
+ * Take a bucket brigade and store the data in a flat char*
+ * @param bb The bucket brigade to create the char* from
+ * @param c The char* to write into
+ * @param len The maximum length of the char array. On return, it is the
+ *            actual length of the char array.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_flatten(apr_bucket_brigade *bb,
+                                              char *c,
+                                              apr_size_t *len);
+
+/**
+ * Creates a pool-allocated string representing a flat bucket brigade
+ * @param bb The bucket brigade to create the char array from
+ * @param c On return, the allocated char array
+ * @param len On return, the length of the char array.
+ * @param pool The pool to allocate the string from.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_pflatten(apr_bucket_brigade *bb, 
+                                               char **c,
+                                               apr_size_t *len,
+                                               apr_pool_t *pool);
+
+/**
+ * Split a brigade to represent one LF line.
+ * @param bbOut The bucket brigade that will have the LF line appended to.
+ * @param bbIn The input bucket brigade to search for a LF-line.
+ * @param block The blocking mode to be used to split the line.
+ * @param maxbytes The maximum bytes to read.  If this many bytes are seen
+ *                 without a LF, the brigade will contain a partial line.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_split_line(apr_bucket_brigade *bbOut,
+                                                 apr_bucket_brigade *bbIn,
+                                                 apr_read_type_e block,
+                                                 apr_off_t maxbytes);
+
+/**
+ * create an iovec of the elements in a bucket_brigade... return number 
+ * of elements used.  This is useful for writing to a file or to the
+ * network efficiently.
+ * @param b The bucket brigade to create the iovec from
+ * @param vec The iovec to create
+ * @param nvec The number of elements in the iovec. On return, it is the
+ *             number of iovec elements actually filled out.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_to_iovec(apr_bucket_brigade *b, 
+                                               struct iovec *vec, int *nvec);
+
+/**
+ * This function writes a list of strings into a bucket brigade. 
+ * @param b The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param va A list of strings to add
+ * @return APR_SUCCESS or error code.
+ */
+APU_DECLARE(apr_status_t) apr_brigade_vputstrs(apr_bucket_brigade *b,
+                                               apr_brigade_flush flush,
+                                               void *ctx,
+                                               va_list va);
+
+/**
+ * This function writes a string into a bucket brigade.
+ * @param b The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param str The string to add
+ * @param nbyte The number of bytes to write
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE(apr_status_t) apr_brigade_write(apr_bucket_brigade *b,
+                                            apr_brigade_flush flush, void *ctx,
+                                            const char *str, apr_size_t nbyte);
+
+/**
+ * This function writes multiple strings into a bucket brigade.
+ * @param b The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param vec The strings to add (address plus length for each)
+ * @param nvec The number of entries in iovec
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE(apr_status_t) apr_brigade_writev(apr_bucket_brigade *b,
+                                             apr_brigade_flush flush,
+                                             void *ctx,
+                                             const struct iovec *vec,
+                                             apr_size_t nvec);
+
+/**
+ * This function writes a string into a bucket brigade.
+ * @param bb The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param str The string to add
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE(apr_status_t) apr_brigade_puts(apr_bucket_brigade *bb,
+                                           apr_brigade_flush flush, void *ctx,
+                                           const char *str);
+
+/**
+ * This function writes a character into a bucket brigade.
+ * @param b The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param c The character to add
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE(apr_status_t) apr_brigade_putc(apr_bucket_brigade *b,
+                                           apr_brigade_flush flush, void *ctx,
+                                           const char c);
+
+/**
+ * This function writes an unspecified number of strings into a bucket brigade.
+ * @param b The bucket brigade to add to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param ... The strings to add
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_brigade_putstrs(apr_bucket_brigade *b,
+                                                     apr_brigade_flush flush,
+                                                     void *ctx, ...);
+
+/**
+ * Evaluate a printf and put the resulting string at the end 
+ * of the bucket brigade.
+ * @param b The brigade to write to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param fmt The format of the string to write
+ * @param ... The arguments to fill out the format
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_brigade_printf(apr_bucket_brigade *b, 
+                                                    apr_brigade_flush flush,
+                                                    void *ctx,
+                                                    const char *fmt, ...)
+        __attribute__((format(printf,4,5)));
+
+/**
+ * Evaluate a printf and put the resulting string at the end 
+ * of the bucket brigade.
+ * @param b The brigade to write to
+ * @param flush The flush function to use if the brigade is full
+ * @param ctx The structure to pass to the flush function
+ * @param fmt The format of the string to write
+ * @param va The arguments to fill out the format
+ * @return APR_SUCCESS or error code
+ */
+APU_DECLARE(apr_status_t) apr_brigade_vprintf(apr_bucket_brigade *b, 
+                                              apr_brigade_flush flush,
+                                              void *ctx,
+                                              const char *fmt, va_list va);
+
+/*  *****  Bucket freelist functions *****  */
+/**
+ * Create a bucket allocator.
+ * @param p This pool's underlying apr_allocator_t is used to allocate memory
+ *          for the bucket allocator.  When the pool is destroyed, the bucket
+ *          allocator's cleanup routine will free all memory that has been
+ *          allocated from it.
+ * @remark  The reason the allocator gets its memory from the pool's
+ *          apr_allocator_t rather than from the pool itself is because
+ *          the bucket allocator will free large memory blocks back to the
+ *          allocator when it's done with them, thereby preventing memory
+ *          footprint growth that would occur if we allocated from the pool.
+ * @warning The allocator must never be used by more than one thread at a time.
+ */
+APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create(apr_pool_t *p);
+
+/**
+ * Create a bucket allocator.
+ * @param allocator This apr_allocator_t is used to allocate both the bucket
+ *          allocator and all memory handed out by the bucket allocator.  The
+ *          caller is responsible for destroying the bucket allocator and the
+ *          apr_allocator_t -- no automatic cleanups will happen.
+ * @warning The allocator must never be used by more than one thread at a time.
+ */
+APU_DECLARE_NONSTD(apr_bucket_alloc_t *) apr_bucket_alloc_create_ex(apr_allocator_t *allocator);
+
+/**
+ * Destroy a bucket allocator.
+ * @param list The allocator to be destroyed
+ */
+APU_DECLARE_NONSTD(void) apr_bucket_alloc_destroy(apr_bucket_alloc_t *list);
+
+/**
+ * Allocate memory for use by the buckets.
+ * @param size The amount to allocate.
+ * @param list The allocator from which to allocate the memory.
+ */
+APU_DECLARE_NONSTD(void *) apr_bucket_alloc(apr_size_t size, apr_bucket_alloc_t *list);
+
+/**
+ * Free memory previously allocated with apr_bucket_alloc().
+ * @param block The block of memory to be freed.
+ */
+APU_DECLARE_NONSTD(void) apr_bucket_free(void *block);
+
+
+/*  *****  Bucket Functions  *****  */
+/**
+ * Free the resources used by a bucket. If multiple buckets refer to
+ * the same resource it is freed when the last one goes away.
+ * @see apr_bucket_delete()
+ * @param e The bucket to destroy
+ */
+#define apr_bucket_destroy(e) do {					\
+        (e)->type->destroy((e)->data);					\
+        (e)->free(e);							\
+    } while (0)
+
+/**
+ * Delete a bucket by removing it from its brigade (if any) and then
+ * destroying it.
+ * @remark This mainly acts as an aid in avoiding code verbosity.  It is
+ * the preferred exact equivalent to:
+ * <pre>
+ *      APR_BUCKET_REMOVE(e);
+ *      apr_bucket_destroy(e);
+ * </pre>
+ * @param e The bucket to delete
+ */
+#define apr_bucket_delete(e) do {					\
+        APR_BUCKET_REMOVE(e);						\
+        apr_bucket_destroy(e);						\
+    } while (0)
+
+/**
+ * read the data from the bucket
+ * @param e The bucket to read from
+ * @param str The location to store the data in
+ * @param len The amount of data read
+ * @param block Whether the read function blocks
+ */
+#define apr_bucket_read(e,str,len,block) (e)->type->read(e, str, len, block)
+
+/**
+ * Setaside data so that stack data is not destroyed on returning from
+ * the function
+ * @param e The bucket to setaside
+ * @param p The pool to setaside into
+ */
+#define apr_bucket_setaside(e,p) (e)->type->setaside(e,p)
+
+/**
+ * Split one bucket in two.
+ * @param e The bucket to split
+ * @param point The offset to split the bucket at
+ */
+#define apr_bucket_split(e,point) (e)->type->split(e, point)
+
+/**
+ * Copy a bucket.
+ * @param e The bucket to copy
+ * @param c Returns a pointer to the new bucket
+ */
+#define apr_bucket_copy(e,c) (e)->type->copy(e, c)
+
+/* Bucket type handling */
+
+/**
+ * This function simply returns APR_SUCCESS to denote that the bucket does
+ * not require anything to happen for its setaside() function. This is
+ * appropriate for buckets that have "immortal" data -- the data will live
+ * at least as long as the bucket.
+ * @param data The bucket to setaside
+ * @param pool The pool defining the desired lifetime of the bucket data
+ * @return APR_SUCCESS
+ */ 
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_setaside_noop(apr_bucket *data,
+                                                          apr_pool_t *pool);
+
+/**
+ * A place holder function that signifies that the setaside function was not
+ * implemented for this bucket
+ * @param data The bucket to setaside
+ * @param pool The pool defining the desired lifetime of the bucket data
+ * @return APR_ENOTIMPL
+ */ 
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_setaside_notimpl(apr_bucket *data,
+                                                             apr_pool_t *pool);
+
+/**
+ * A place holder function that signifies that the split function was not
+ * implemented for this bucket
+ * @param data The bucket to split
+ * @param point The location to split the bucket
+ * @return APR_ENOTIMPL
+ */ 
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_split_notimpl(apr_bucket *data,
+                                                          apr_size_t point);
+
+/**
+ * A place holder function that signifies that the copy function was not
+ * implemented for this bucket
+ * @param e The bucket to copy
+ * @param c Returns a pointer to the new bucket
+ * @return APR_ENOTIMPL
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_copy_notimpl(apr_bucket *e,
+                                                         apr_bucket **c);
+
+/**
+ * A place holder function that signifies that this bucket does not need
+ * to do anything special to be destroyed.  That's only the case for buckets
+ * that either have no data (metadata buckets) or buckets whose data pointer
+ * points to something that's not a bucket-type-specific structure, as with
+ * simple buckets where data points to a string and pipe buckets where data
+ * points directly to the apr_file_t.
+ * @param data The bucket data to destroy
+ */ 
+APU_DECLARE_NONSTD(void) apr_bucket_destroy_noop(void *data);
+
+/**
+ * There is no apr_bucket_destroy_notimpl, because destruction is required
+ * to be implemented (it could be a noop, but only if that makes sense for
+ * the bucket type)
+ */
+
+/* There is no apr_bucket_read_notimpl, because it is a required function
+ */
+
+
+/* All of the bucket types implemented by the core */
+/**
+ * The flush bucket type.  This signifies that all data should be flushed to
+ * the next filter.  The flush bucket should be sent with the other buckets.
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_flush;
+/**
+ * The EOS bucket type.  This signifies that there will be no more data, ever.
+ * All filters MUST send all data to the next filter when they receive a
+ * bucket of this type
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_eos;
+/**
+ * The FILE bucket type.  This bucket represents a file on disk
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_file;
+/**
+ * The HEAP bucket type.  This bucket represents a data allocated from the
+ * heap.
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_heap;
+#if APR_HAS_MMAP
+/**
+ * The MMAP bucket type.  This bucket represents an MMAP'ed file
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_mmap;
+#endif
+/**
+ * The POOL bucket type.  This bucket represents a data that was allocated
+ * from a pool.  IF this bucket is still available when the pool is cleared,
+ * the data is copied on to the heap.
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_pool;
+/**
+ * The PIPE bucket type.  This bucket represents a pipe to another program.
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_pipe;
+/**
+ * The IMMORTAL bucket type.  This bucket represents a segment of data that
+ * the creator is willing to take responsibility for.  The core will do
+ * nothing with the data in an immortal bucket
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_immortal;
+/**
+ * The TRANSIENT bucket type.  This bucket represents a data allocated off
+ * the stack.  When the setaside function is called, this data is copied on
+ * to the heap
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_transient;
+/**
+ * The SOCKET bucket type.  This bucket represents a socket to another machine
+ */
+APU_DECLARE_DATA extern const apr_bucket_type_t apr_bucket_type_socket;
+
+
+/*  *****  Simple buckets  *****  */
+
+/**
+ * Split a simple bucket into two at the given point.  Most non-reference
+ * counting buckets that allow multiple references to the same block of
+ * data (eg transient and immortal) will use this as their split function
+ * without any additional type-specific handling.
+ * @param b The bucket to be split
+ * @param point The offset of the first byte in the new bucket
+ * @return APR_EINVAL if the point is not within the bucket;
+ *         APR_ENOMEM if allocation failed;
+ *         or APR_SUCCESS
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_split(apr_bucket *b,
+                                                         apr_size_t point);
+
+/**
+ * Copy a simple bucket.  Most non-reference-counting buckets that allow
+ * multiple references to the same block of data (eg transient and immortal)
+ * will use this as their copy function without any additional type-specific
+ * handling.
+ * @param a The bucket to copy
+ * @param b Returns a pointer to the new bucket
+ * @return APR_ENOMEM if allocation failed;
+ *         or APR_SUCCESS
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_simple_copy(apr_bucket *a,
+                                                        apr_bucket **b);
+
+
+/*  *****  Shared, reference-counted buckets  *****  */
+
+/**
+ * Initialize a bucket containing reference-counted data that may be
+ * shared. The caller must allocate the bucket if necessary and
+ * initialize its type-dependent fields, and allocate and initialize
+ * its own private data structure. This function should only be called
+ * by type-specific bucket creation functions.
+ * @param b The bucket to initialize
+ * @param data A pointer to the private data structure
+ *             with the reference count at the start
+ * @param start The start of the data in the bucket
+ *              relative to the private base pointer
+ * @param length The length of the data in the bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_shared_make(apr_bucket *b, void *data,
+				                 apr_off_t start, 
+                                                 apr_size_t length);
+
+/**
+ * Decrement the refcount of the data in the bucket. This function
+ * should only be called by type-specific bucket destruction functions.
+ * @param data The private data pointer from the bucket to be destroyed
+ * @return TRUE or FALSE; TRUE if the reference count is now
+ *         zero, indicating that the shared resource itself can
+ *         be destroyed by the caller.
+ */
+APU_DECLARE(int) apr_bucket_shared_destroy(void *data);
+
+/**
+ * Split a bucket into two at the given point, and adjust the refcount
+ * to the underlying data. Most reference-counting bucket types will
+ * be able to use this function as their split function without any
+ * additional type-specific handling.
+ * @param b The bucket to be split
+ * @param point The offset of the first byte in the new bucket
+ * @return APR_EINVAL if the point is not within the bucket;
+ *         APR_ENOMEM if allocation failed;
+ *         or APR_SUCCESS
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_shared_split(apr_bucket *b,
+                                                         apr_size_t point);
+
+/**
+ * Copy a refcounted bucket, incrementing the reference count. Most
+ * reference-counting bucket types will be able to use this function
+ * as their copy function without any additional type-specific handling.
+ * @param a The bucket to copy
+ * @param b Returns a pointer to the new bucket
+ * @return APR_ENOMEM if allocation failed;
+           or APR_SUCCESS
+ */
+APU_DECLARE_NONSTD(apr_status_t) apr_bucket_shared_copy(apr_bucket *a,
+                                                        apr_bucket **b);
+
+
+/*  *****  Functions to Create Buckets of varying types  *****  */
+/*
+ * Each bucket type foo has two initialization functions:
+ * apr_bucket_foo_make which sets up some already-allocated memory as a
+ * bucket of type foo; and apr_bucket_foo_create which allocates memory
+ * for the bucket, calls apr_bucket_make_foo, and initializes the
+ * bucket's list pointers. The apr_bucket_foo_make functions are used
+ * inside the bucket code to change the type of buckets in place;
+ * other code should call apr_bucket_foo_create. All the initialization
+ * functions change nothing if they fail.
+ */
+
+/**
+ * Create an End of Stream bucket.  This indicates that there is no more data
+ * coming from down the filter stack.  All filters should flush at this point.
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_eos_create(apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in an EOS bucket.  This indicates that there is no 
+ * more data coming from down the filter stack.  All filters should flush at 
+ * this point.
+ * @param b The bucket to make into an EOS bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_eos_make(apr_bucket *b);
+
+/**
+ * Create a flush  bucket.  This indicates that filters should flush their
+ * data.  There is no guarantee that they will flush it, but this is the
+ * best we can do.
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_flush_create(apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a FLUSH  bucket.  This indicates that filters 
+ * should flush their data.  There is no guarantee that they will flush it, 
+ * but this is the best we can do.
+ * @param b The bucket to make into a FLUSH bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_flush_make(apr_bucket *b);
+
+/**
+ * Create a bucket referring to long-lived data.
+ * @param buf The data to insert into the bucket
+ * @param nbyte The size of the data to insert.
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_immortal_create(const char *buf, 
+                                                     apr_size_t nbyte,
+                                                     apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to long-lived data
+ * @param b The bucket to make into a IMMORTAL bucket
+ * @param buf The data to insert into the bucket
+ * @param nbyte The size of the data to insert.
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_immortal_make(apr_bucket *b, 
+                                                   const char *buf, 
+                                                   apr_size_t nbyte);
+
+/**
+ * Create a bucket referring to data on the stack.
+ * @param buf The data to insert into the bucket
+ * @param nbyte The size of the data to insert.
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_transient_create(const char *buf, 
+                                                      apr_size_t nbyte,
+                                                      apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to stack data
+ * @param b The bucket to make into a TRANSIENT bucket
+ * @param buf The data to insert into the bucket
+ * @param nbyte The size of the data to insert.
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_transient_make(apr_bucket *b, 
+                                                    const char *buf,
+                                                    apr_size_t nbyte);
+
+/**
+ * Create a bucket referring to memory on the heap. If the caller asks
+ * for the data to be copied, this function always allocates 4K of
+ * memory so that more data can be added to the bucket without
+ * requiring another allocation. Therefore not all the data may be put
+ * into the bucket. If copying is not requested then the bucket takes
+ * over responsibility for free()ing the memory.
+ * @param buf The buffer to insert into the bucket
+ * @param nbyte The size of the buffer to insert.
+ * @param free_func Function to use to free the data; NULL indicates that the
+ *                  bucket should make a copy of the data
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_heap_create(const char *buf, 
+                                                 apr_size_t nbyte,
+                                                 void (*free_func)(void *data),
+                                                 apr_bucket_alloc_t *list);
+/**
+ * Make the bucket passed in a bucket refer to heap data
+ * @param b The bucket to make into a HEAP bucket
+ * @param buf The buffer to insert into the bucket
+ * @param nbyte The size of the buffer to insert.
+ * @param free_func Function to use to free the data; NULL indicates that the
+ *                  bucket should make a copy of the data
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_heap_make(apr_bucket *b, const char *buf,
+                                               apr_size_t nbyte,
+                                               void (*free_func)(void *data));
+
+/**
+ * Create a bucket referring to memory allocated from a pool.
+ *
+ * @param buf The buffer to insert into the bucket
+ * @param length The number of bytes referred to by this bucket
+ * @param pool The pool the memory was allocated from
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_pool_create(const char *buf, 
+                                                 apr_size_t length,
+                                                 apr_pool_t *pool,
+                                                 apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to pool data
+ * @param b The bucket to make into a pool bucket
+ * @param buf The buffer to insert into the bucket
+ * @param length The number of bytes referred to by this bucket
+ * @param pool The pool the memory was allocated from
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_pool_make(apr_bucket *b, const char *buf,
+                                               apr_size_t length, 
+                                               apr_pool_t *pool);
+
+#if APR_HAS_MMAP
+/**
+ * Create a bucket referring to mmap()ed memory.
+ * @param mm The mmap to insert into the bucket
+ * @param start The offset of the first byte in the mmap
+ *              that this bucket refers to
+ * @param length The number of bytes referred to by this bucket
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_mmap_create(apr_mmap_t *mm, 
+                                                 apr_off_t start,
+                                                 apr_size_t length,
+                                                 apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to an MMAP'ed file
+ * @param b The bucket to make into a MMAP bucket
+ * @param mm The mmap to insert into the bucket
+ * @param start The offset of the first byte in the mmap
+ *              that this bucket refers to
+ * @param length The number of bytes referred to by this bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_mmap_make(apr_bucket *b, apr_mmap_t *mm,
+                                               apr_off_t start, 
+                                               apr_size_t length);
+#endif
+
+/**
+ * Create a bucket referring to a socket.
+ * @param thissock The socket to put in the bucket
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_socket_create(apr_socket_t *thissock,
+                                                   apr_bucket_alloc_t *list);
+/**
+ * Make the bucket passed in a bucket refer to a socket
+ * @param b The bucket to make into a SOCKET bucket
+ * @param thissock The socket to put in the bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_socket_make(apr_bucket *b, 
+                                                 apr_socket_t *thissock);
+
+/**
+ * Create a bucket referring to a pipe.
+ * @param thispipe The pipe to put in the bucket
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_pipe_create(apr_file_t *thispipe,
+                                                 apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to a pipe
+ * @param b The bucket to make into a PIPE bucket
+ * @param thispipe The pipe to put in the bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_pipe_make(apr_bucket *b, 
+                                               apr_file_t *thispipe);
+
+/**
+ * Create a bucket referring to a file.
+ * @param fd The file to put in the bucket
+ * @param offset The offset where the data of interest begins in the file
+ * @param len The amount of data in the file we are interested in
+ * @param p The pool into which any needed structures should be created
+ *          while reading from this file bucket
+ * @param list The freelist from which this bucket should be allocated
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_file_create(apr_file_t *fd,
+                                                 apr_off_t offset,
+                                                 apr_size_t len, 
+                                                 apr_pool_t *p,
+                                                 apr_bucket_alloc_t *list);
+
+/**
+ * Make the bucket passed in a bucket refer to a file
+ * @param b The bucket to make into a FILE bucket
+ * @param fd The file to put in the bucket
+ * @param offset The offset where the data of interest begins in the file
+ * @param len The amount of data in the file we are interested in
+ * @param p The pool into which any needed structures should be created
+ *          while reading from this file bucket
+ * @return The new bucket, or NULL if allocation failed
+ */
+APU_DECLARE(apr_bucket *) apr_bucket_file_make(apr_bucket *b, apr_file_t *fd,
+                                               apr_off_t offset,
+                                               apr_size_t len, apr_pool_t *p);
+
+/**
+ * Enable or disable memory-mapping for a FILE bucket (default is enabled)
+ * @param b The bucket
+ * @param enabled Whether memory-mapping should be enabled
+ * @return APR_SUCCESS normally, or an error code if the operation fails
+ */
+APU_DECLARE(apr_status_t) apr_bucket_file_enable_mmap(apr_bucket *b,
+                                                      int enabled);
+
+/** @} */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !APR_BUCKETS_H */