[Spice-devel] [PATCH spice-server 03/13] char-device: Allocate all write buffer in a single block

[Frediano Ziglio]

There are no much data other than the buffer, reduce the
allocations.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/char-device.c | 27 +++++++++++++++------------
 server/char-device.h |  2 +-
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/server/char-device.c b/server/char-device.c
index 89581ea42..059e8e5f6 100644
--- a/server/char-device.c
+++ b/server/char-device.c
@@ -149,11 +149,9 @@ red_char_device_remove_client(RedCharDevice *dev, RedClient *client)
 
 static void red_char_device_write_buffer_free(RedCharDeviceWriteBuffer *buf)
 {
-    if (buf == NULL)
-        return;
-
-    g_free(buf->buf);
-    g_free(buf);
+    if (buf) {
+        g_free(buf->priv);
+    }
 }
 
 static void write_buffers_queue_free(GQueue *write_queue)
@@ -542,22 +540,27 @@ red_char_device_write_buffer_get(RedCharDevice *dev, RedClient *client, int size
     ret = g_queue_pop_tail(&dev->priv->write_bufs_pool);
     if (ret) {
         dev->priv->cur_pool_size -= ret->buf_size;
-    } else {
+        if (ret->buf_size < size) {
+            spice_assert(!spice_extra_checks || ret->priv->refs == 1);
+            red_char_device_write_buffer_free(ret);
+            ret = NULL;
+        }
+    }
+    if (ret == NULL) {
         struct RedCharDeviceWriteBufferFull {
-            RedCharDeviceWriteBuffer buffer;
             RedCharDeviceWriteBufferPrivate priv;
+            RedCharDeviceWriteBuffer buffer;
         } *write_buf;
-        write_buf = g_new0(struct RedCharDeviceWriteBufferFull, 1);
+        write_buf = g_malloc(sizeof(struct RedCharDeviceWriteBufferFull) + size);
+        memset(write_buf, 0, sizeof(*write_buf));
+        write_buf->priv.refs = 1;
         ret = &write_buf->buffer;
+        ret->buf_size = size;
         ret->priv = &write_buf->priv;
     }
 
     spice_assert(!ret->buf_used);
 
-    if (ret->buf_size < size) {
-        ret->buf = g_realloc(ret->buf, size);
-        ret->buf_size = size;
-    }
     ret->priv->origin = origin;
 
     if (origin == WRITE_BUFFER_ORIGIN_CLIENT) {
diff --git a/server/char-device.h b/server/char-device.h
index 7d3ad8b3a..5327c25e5 100644
--- a/server/char-device.h
+++ b/server/char-device.h
@@ -151,11 +151,11 @@ GType red_char_device_get_type(void) G_GNUC_CONST;
 /* buffer that is used for writing to the device */
 typedef struct RedCharDeviceWriteBufferPrivate RedCharDeviceWriteBufferPrivate;
 typedef struct RedCharDeviceWriteBuffer {
-    uint8_t *buf;
     uint32_t buf_size;
     uint32_t buf_used;
 
     RedCharDeviceWriteBufferPrivate *priv;
+    uint8_t buf[0];
 } RedCharDeviceWriteBuffer;
 
 void red_char_device_reset_dev_instance(RedCharDevice *dev,
-- 
2.20.1