/* * 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 = qemu_mallocz(size); return (p); } void vnc_zlib_zfree(void *x, void *addr) { qemu_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); }