[Spice-devel] [PATCH spice-gtk 1/4] Usbredir: enable lz4 compression

Snir Sheriber ssheribe at redhat.com
Sun May 22 12:51:26 UTC 2016


Compressed message type is CompressedData which contains compression
type (1 byte) followed by the uncompressed data size (4 bytes) followed
by the compressed data size (4 bytes) followed by the compressed data

If SPICE_SPICEVMC_CAP_DATA_COMPRESS_LZ4 capability is available &&
data_size > COMPRESS_THRESHOLD data will be sent compressed otherwise
data will be sent uncompressed (as well if compression has failed)
---
 src/channel-usbredir.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 129 insertions(+), 6 deletions(-)

diff --git a/src/channel-usbredir.c b/src/channel-usbredir.c
index c8a2da9..3e2951d 100644
--- a/src/channel-usbredir.c
+++ b/src/channel-usbredir.c
@@ -24,6 +24,9 @@
 #ifdef USE_USBREDIR
 #include <glib/gi18n.h>
 #include <usbredirhost.h>
+#ifdef USE_LZ4
+#include <lz4.h>
+#endif
 #ifdef USE_POLKIT
 #include "usb-acl-helper.h"
 #endif
@@ -32,6 +35,7 @@
 #include "usbutil.h"
 #endif
 
+#include "common/log.h"
 #include "spice-client.h"
 #include "spice-common.h"
 
@@ -51,6 +55,7 @@
 
 #ifdef USE_USBREDIR
 
+#define COMPRESS_THRESHOLD 1000
 #define SPICE_USBREDIR_CHANNEL_GET_PRIVATE(obj)                                  \
     (G_TYPE_INSTANCE_GET_PRIVATE((obj), SPICE_TYPE_USBREDIR_CHANNEL, SpiceUsbredirChannelPrivate))
 
@@ -233,6 +238,7 @@ static void channel_set_handlers(SpiceChannelClass *klass)
 {
     static const spice_msg_handler handlers[] = {
         [ SPICE_MSG_SPICEVMC_DATA ] = usbredir_handle_msg,
+        [ SPICE_MSG_SPICEVMC_COMPRESSED_DATA ] = usbredir_handle_msg,
     };
 
     spice_channel_set_handlers(klass, handlers, G_N_ELEMENTS(handlers));
@@ -269,6 +275,9 @@ void spice_usbredir_channel_set_context(SpiceUsbredirChannel *channel,
 #if USBREDIR_VERSION >= 0x000701
     usbredirhost_set_buffered_output_size_cb(priv->host, usbredir_buffered_output_size_callback);
 #endif
+#ifdef USE_LZ4
+    spice_channel_set_capability(channel, SPICE_SPICEVMC_CAP_DATA_COMPRESS_LZ4);
+#endif
 }
 
 static gboolean spice_usbredir_channel_open_device(
@@ -632,11 +641,77 @@ static void usbredir_free_write_cb_data(uint8_t *data, void *user_data)
     usbredirhost_free_write_buffer(priv->host, data);
 }
 
+#ifdef USE_LZ4
+static void usbredir_free_write_cb_compressed_data(uint8_t *data, void *user_data)
+{
+    SpiceUsbredirChannel *channel = user_data;
+    SpiceUsbredirChannelPrivate *priv = channel->priv;
+
+    usbredirhost_free_write_buffer(priv->host,
+                                   (uint8_t*)SPICE_CONTAINEROF(data, SpiceMsgCompressedData, compressed_data));
+}
+
+static int try_write_compress_LZ4(SpiceUsbredirChannel *channel, uint8_t *data, int count) {
+    SpiceChannelPrivate *c;
+    SpiceMsgOut *msg_out_compressed;
+    int bound, compressed_data_count;
+    SpiceMsgCompressedData *compressed_data_msg;
+
+    c = SPICE_CHANNEL(channel)->priv;
+    if (g_socket_get_family(c->sock) == G_SOCKET_FAMILY_UNIX) {
+        /* AF_LOCAL socket - data will not be compressed */
+        return FALSE;
+    }
+    if (count <= COMPRESS_THRESHOLD) {
+        /* Not enough data to compress */
+        return FALSE;
+    }
+    if (!spice_channel_test_capability(SPICE_CHANNEL(channel),
+                                       SPICE_SPICEVMC_CAP_DATA_COMPRESS_LZ4)) {
+        /* No server compression capability - data will not be compressed */
+        return FALSE;
+    }
+    bound = LZ4_compressBound(count);
+    if (bound == 0) {
+        /* Invalid bound - data will not be compressed */
+        return FALSE;
+    }
+    compressed_data_msg = (SpiceMsgCompressedData*)spice_malloc(sizeof(SpiceMsgCompressedData) + bound);
+    compressed_data_msg->uncompressed_size = count;
+    compressed_data_msg->type = SPICE_DATA_COMPRESSION_TYPE_LZ4;
+    compressed_data_count = LZ4_compress_default((char*)data,
+                                                 (char*)compressed_data_msg->compressed_data,
+                                                 count,
+                                                 bound);
+    if (compressed_data_count > 0) {
+        compressed_data_msg->compressed_size = compressed_data_count;
+        msg_out_compressed = spice_msg_out_new(SPICE_CHANNEL(channel),
+                                               SPICE_MSGC_SPICEVMC_COMPRESSED_DATA);
+        msg_out_compressed->marshallers->msg_SpiceMsgCompressedData(msg_out_compressed->marshaller,
+                                                                    compressed_data_msg);
+        spice_marshaller_add_ref_full(msg_out_compressed->marshaller,
+                                      compressed_data_msg->compressed_data,
+                                      compressed_data_count,
+                                      usbredir_free_write_cb_compressed_data,
+                                      channel);
+        spice_msg_out_send(msg_out_compressed);
+        return TRUE;
+    }
+    /* if not - free & fallback to sending the message uncompressed */
+    free(compressed_data_msg);
+    return FALSE;
+}
+#endif
+
 static int usbredir_write_callback(void *user_data, uint8_t *data, int count)
 {
     SpiceUsbredirChannel *channel = user_data;
     SpiceMsgOut *msg_out;
 
+#ifdef USE_LZ4
+    if (try_write_compress_LZ4(channel, data, count))
+        return count;
+#endif
     msg_out = spice_msg_out_new(SPICE_CHANNEL(channel),
                                 SPICE_MSGC_SPICEVMC_DATA);
     spice_marshaller_add_ref_full(msg_out->marshaller, data, count,
@@ -724,11 +799,49 @@ static void spice_usbredir_channel_up(SpiceChannel *c)
     usbredirhost_write_guest_data(priv->host);
 }
 
+static int try_handle_compressed_msg(SpiceMsgCompressedData *compressed_data_msg,
+                                     uint8_t **buf,
+                                     int *size) {
+    uint32_t decompressed_size = 0;
+    char *decompressed = NULL;
+
+    if (compressed_data_msg->uncompressed_size == 0) {
+        spice_warning("Invalid uncompressed_size");
+        return FALSE;
+    }
+
+    switch (compressed_data_msg->type) {
+#ifdef USE_LZ4
+    case SPICE_DATA_COMPRESSION_TYPE_LZ4:
+        decompressed = g_malloc(compressed_data_msg->uncompressed_size);
+        decompressed_size = LZ4_decompress_safe ((char*)compressed_data_msg->compressed_data,
+                                                 decompressed,
+                                                 compressed_data_msg->compressed_size,
+                                                 compressed_data_msg->uncompressed_size);
+        break;
+#endif
+    default:
+        spice_warning("Unknown Compression Type");
+        return FALSE;
+    }
+    if (decompressed_size != compressed_data_msg->uncompressed_size) {
+        spice_warning("Decompress Error decompressed_size=%d expected=%d",
+                      decompressed_size, compressed_data_msg->uncompressed_size);
+        g_free(decompressed);
+        return FALSE;
+    }
+
+    *size = decompressed_size;
+    *buf = (uint8_t*)decompressed;
+    return TRUE;
+
+}
+
 static void usbredir_handle_msg(SpiceChannel *c, SpiceMsgIn *in)
 {
     SpiceUsbredirChannel *channel = SPICE_USBREDIR_CHANNEL(c);
     SpiceUsbredirChannelPrivate *priv = channel->priv;
-    int r, size;
+    int r = 0, size;
     uint8_t *buf;
 
     g_return_if_fail(priv->host != NULL);
@@ -736,13 +849,23 @@ static void usbredir_handle_msg(SpiceChannel *c, SpiceMsgIn *in)
     /* No recursion allowed! */
     g_return_if_fail(priv->read_buf == NULL);
 
-    buf = spice_msg_in_raw(in, &size);
-    priv->read_buf = buf;
-    priv->read_buf_size = size;
+    if (spice_msg_in_type(in) == SPICE_MSG_SPICEVMC_COMPRESSED_DATA) {
+        SpiceMsgCompressedData *compressed_data_msg = spice_msg_in_parsed(in);
+        if (try_handle_compressed_msg(compressed_data_msg, &buf, &size)) {
+            priv->read_buf_size = size;
+            priv->read_buf = buf;
+        } else {
+            r = usbredirhost_read_parse_error;
+        }
+    } else { /* Regular SPICE_MSG_SPICEVMC_DATA msg */
+        buf = spice_msg_in_raw(in, &size);
+        priv->read_buf_size = size;
+        priv->read_buf = buf;
+    }
 
     spice_usbredir_channel_lock(channel);
-
-    r = usbredirhost_read_guest_data(priv->host);
+    if (r == 0)
+        r = usbredirhost_read_guest_data(priv->host);
     if (r != 0) {
         SpiceUsbDevice *spice_device = priv->spice_device;
         device_error_data err_data;
-- 
2.5.5



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