1 files changed, 142 insertions, 0 deletions
diff --git a/vnc-encoding-zlib.c b/vnc-encoding-zlib.c
new file mode 100644
index 000000000..4a495adf9
--- /dev/null
+++ b/vnc-encoding-zlib.c
@@ -0,0 +1,142 @@
+/*
+ * 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
+
+static void *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);
+}
+
+static void zfree(void *x, void *addr)
+{
+    qemu_free(addr);
+}
+
+static void vnc_zlib_start(VncState *vs)
+{
+    buffer_reset(&vs->zlib);
+
+    // make the output buffer be the zlib buffer, so we can compress it later
+    vs->zlib_tmp = vs->output;
+    vs->output = vs->zlib;
+}
+
+static int vnc_zlib_stop(VncState *vs, int stream_id)
+{
+    z_streamp zstream = &vs->zlib_stream[stream_id];
+    int previous_out;
+
+    // switch back to normal output/zlib buffers
+    vs->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 %d\n", stream_id);
+        VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs);
+        zstream->zalloc = zalloc;
+        zstream->zfree = 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;
+        }
+
+        zstream->opaque = vs;
+    }
+
+    // XXX what to do if tight_compression changed in between?
+
+    // reserve memory in output buffer
+    buffer_reserve(&vs->output, vs->zlib.offset + 64);
+
+    // set pointers
+    zstream->next_in = vs->zlib.buffer;
+    zstream->avail_in = vs->zlib.offset;
+    zstream->next_out = vs->output.buffer + vs->output.offset;
+    zstream->avail_out = vs->output.capacity - vs->output.offset;
+    zstream->data_type = Z_BINARY;
+    previous_out = zstream->total_out;
+
+    // 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 zstream->total_out - previous_out;
+}
+
+void 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, 0);
+
+    if (bytes_written == -1)
+        return;
+
+    // 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;
+}
+
+void vnc_zlib_init(VncState *vs)
+{
+    int i;
+    for (i=0; i<(sizeof(vs->zlib_stream) / sizeof(z_stream)); i++)
+        vs->zlib_stream[i].opaque = NULL;
+}