diff options
Diffstat (limited to 'qemu/ui/vnc-enc-zlib.c')
-rw-r--r-- | qemu/ui/vnc-enc-zlib.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/qemu/ui/vnc-enc-zlib.c b/qemu/ui/vnc-enc-zlib.c new file mode 100644 index 000000000..d1b97f251 --- /dev/null +++ b/qemu/ui/vnc-enc-zlib.c @@ -0,0 +1,152 @@ +/* + * QEMU VNC display driver: zlib encoding + * + * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws> + * Copyright (C) 2006 Fabrice Bellard + * Copyright (C) 2009 Red Hat, Inc + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "vnc.h" + +#define ZALLOC_ALIGNMENT 16 + +void *vnc_zlib_zalloc(void *x, unsigned items, unsigned size) +{ + void *p; + + size *= items; + size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1); + + p = g_malloc0(size); + + return (p); +} + +void vnc_zlib_zfree(void *x, void *addr) +{ + g_free(addr); +} + +static void vnc_zlib_start(VncState *vs) +{ + buffer_reset(&vs->zlib.zlib); + + // make the output buffer be the zlib buffer, so we can compress it later + vs->zlib.tmp = vs->output; + vs->output = vs->zlib.zlib; +} + +static int vnc_zlib_stop(VncState *vs) +{ + z_streamp zstream = &vs->zlib.stream; + int previous_out; + + // switch back to normal output/zlib buffers + vs->zlib.zlib = vs->output; + vs->output = vs->zlib.tmp; + + // compress the zlib buffer + + // initialize the stream + // XXX need one stream per session + if (zstream->opaque != vs) { + int err; + + VNC_DEBUG("VNC: initializing zlib stream\n"); + VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs); + zstream->zalloc = vnc_zlib_zalloc; + zstream->zfree = vnc_zlib_zfree; + + err = deflateInit2(zstream, vs->tight.compression, Z_DEFLATED, MAX_WBITS, + MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY); + + if (err != Z_OK) { + fprintf(stderr, "VNC: error initializing zlib\n"); + return -1; + } + + vs->zlib.level = vs->tight.compression; + zstream->opaque = vs; + } + + if (vs->tight.compression != vs->zlib.level) { + if (deflateParams(zstream, vs->tight.compression, + Z_DEFAULT_STRATEGY) != Z_OK) { + return -1; + } + vs->zlib.level = vs->tight.compression; + } + + // reserve memory in output buffer + buffer_reserve(&vs->output, vs->zlib.zlib.offset + 64); + + // set pointers + zstream->next_in = vs->zlib.zlib.buffer; + zstream->avail_in = vs->zlib.zlib.offset; + zstream->next_out = vs->output.buffer + vs->output.offset; + zstream->avail_out = vs->output.capacity - vs->output.offset; + previous_out = zstream->avail_out; + zstream->data_type = Z_BINARY; + + // start encoding + if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) { + fprintf(stderr, "VNC: error during zlib compression\n"); + return -1; + } + + vs->output.offset = vs->output.capacity - zstream->avail_out; + return previous_out - zstream->avail_out; +} + +int vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h) +{ + int old_offset, new_offset, bytes_written; + + vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB); + + // remember where we put in the follow-up size + old_offset = vs->output.offset; + vnc_write_s32(vs, 0); + + // compress the stream + vnc_zlib_start(vs); + vnc_raw_send_framebuffer_update(vs, x, y, w, h); + bytes_written = vnc_zlib_stop(vs); + + if (bytes_written == -1) + return 0; + + // hack in the size + new_offset = vs->output.offset; + vs->output.offset = old_offset; + vnc_write_u32(vs, bytes_written); + vs->output.offset = new_offset; + + return 1; +} + +void vnc_zlib_clear(VncState *vs) +{ + if (vs->zlib.stream.opaque) { + deflateEnd(&vs->zlib.stream); + } + buffer_free(&vs->zlib.zlib); +} |