BufferedFile: append, then flush

[qemu.git] / buffered_file.c

diff --git a/buffered_file.c b/buffered_file.c
index 4f4976387a62ebbfddbe6e97f8e96d1e0f81f2c7..71558009bda18b2621cd0b6d101c1a1e2e014246 100644 (file)
--- a/buffered_file.c
+++ b/buffered_file.c
@@ -9,6 +9,8 @@
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
  *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
  */
 
 #include "qemu-common.h"
@@ -48,20 +50,12 @@ static void buffered_append(QEMUFileBuffered *s,
                             const uint8_t *buf, size_t size)
 {
     if (size > (s->buffer_capacity - s->buffer_size)) {
-        void *tmp;
-
         DPRINTF("increasing buffer capacity from %zu by %zu\n",
                 s->buffer_capacity, size + 1024);
 
         s->buffer_capacity += size + 1024;
 
-        tmp = g_realloc(s->buffer, s->buffer_capacity);
-        if (tmp == NULL) {
-            fprintf(stderr, "qemu file buffer expansion failed\n");
-            exit(1);
-        }
-
-        s->buffer = tmp;
+        s->buffer = g_realloc(s->buffer, s->buffer_capacity);
     }
 
     memcpy(s->buffer + s->buffer_size, buf, size);
@@ -71,15 +65,17 @@ static void buffered_append(QEMUFileBuffered *s,
 static void buffered_flush(QEMUFileBuffered *s)
 {
     size_t offset = 0;
+    int error;
 
-    if (qemu_file_has_error(s->file)) {
-        DPRINTF("flush when error, bailing\n");
+    error = qemu_file_get_error(s->file);
+    if (error != 0) {
+        DPRINTF("flush when error, bailing: %s\n", strerror(-error));
         return;
     }
 
     DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size);
 
-    while (offset < s->buffer_size) {
+    while (s->bytes_xfer < s->xfer_limit && offset < s->buffer_size) {
         ssize_t ret;
 
         ret = s->put_buffer(s->opaque, s->buffer + offset,
@@ -92,11 +88,12 @@ static void buffered_flush(QEMUFileBuffered *s)
 
         if (ret <= 0) {
             DPRINTF("error flushing data, %zd\n", ret);
-            qemu_file_set_error(s->file);
+            qemu_file_set_error(s->file, ret);
             break;
         } else {
             DPRINTF("flushed %zd byte(s)\n", ret);
             offset += ret;
+            s->bytes_xfer += ret;
         }
     }
 
@@ -108,61 +105,35 @@ static void buffered_flush(QEMUFileBuffered *s)
 static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
 {
     QEMUFileBuffered *s = opaque;
-    int offset = 0;
-    ssize_t ret;
+    int error;
 
     DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
 
-    if (qemu_file_has_error(s->file)) {
-        DPRINTF("flush when error, bailing\n");
-        return -EINVAL;
+    error = qemu_file_get_error(s->file);
+    if (error) {
+        DPRINTF("flush when error, bailing: %s\n", strerror(-error));
+        return error;
     }
 
     DPRINTF("unfreezing output\n");
     s->freeze_output = 0;
 
-    buffered_flush(s);
-
-    while (!s->freeze_output && offset < size) {
-        if (s->bytes_xfer > s->xfer_limit) {
-            DPRINTF("transfer limit exceeded when putting\n");
-            break;
-        }
-
-        ret = s->put_buffer(s->opaque, buf + offset, size - offset);
-        if (ret == -EAGAIN) {
-            DPRINTF("backend not ready, freezing\n");
-            s->freeze_output = 1;
-            break;
-        }
-
-        if (ret <= 0) {
-            DPRINTF("error putting\n");
-            qemu_file_set_error(s->file);
-            offset = -EINVAL;
-            break;
-        }
-
-        DPRINTF("put %zd byte(s)\n", ret);
-        offset += ret;
-        s->bytes_xfer += ret;
-    }
-
-    if (offset >= 0) {
+    if (size > 0) {
         DPRINTF("buffering %d bytes\n", size - offset);
-        buffered_append(s, buf + offset, size - offset);
-        offset = size;
+        buffered_append(s, buf, size);
     }
 
+    buffered_flush(s);
+
     if (pos == 0 && size == 0) {
         DPRINTF("file is ready\n");
-        if (s->bytes_xfer <= s->xfer_limit) {
+        if (!s->freeze_output && s->bytes_xfer < s->xfer_limit) {
             DPRINTF("notifying client\n");
             s->put_ready(s->opaque);
         }
     }
 
-    return offset;
+    return size;
 }
 
 static int buffered_close(void *opaque)
@@ -172,7 +143,8 @@ static int buffered_close(void *opaque)
 
     DPRINTF("closing\n");
 
-    while (!qemu_file_has_error(s->file) && s->buffer_size) {
+    s->xfer_limit = INT_MAX;
+    while (!qemu_file_get_error(s->file) && s->buffer_size) {
         buffered_flush(s);
         if (s->freeze_output)
             s->wait_for_unfreeze(s->opaque);
@@ -192,14 +164,16 @@ static int buffered_close(void *opaque)
  * The meaning of the return values is:
  *   0: We can continue sending
  *   1: Time to stop
- *  -1: There has been an error
+ *   negative: There has been an error
  */
 static int buffered_rate_limit(void *opaque)
 {
     QEMUFileBuffered *s = opaque;
+    int ret;
 
-    if (qemu_file_has_error(s->file)) {
-        return -1;
+    ret = qemu_file_get_error(s->file);
+    if (ret) {
+        return ret;
     }
     if (s->freeze_output)
         return 1;
@@ -213,9 +187,9 @@ static int buffered_rate_limit(void *opaque)
 static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
 {
     QEMUFileBuffered *s = opaque;
-    if (qemu_file_has_error(s->file))
+    if (qemu_file_get_error(s->file)) {
         goto out;
-
+    }
     if (new_rate > SIZE_MAX) {
         new_rate = SIZE_MAX;
     }
@@ -237,7 +211,7 @@ static void buffered_rate_tick(void *opaque)
 {
     QEMUFileBuffered *s = opaque;
 
-    if (qemu_file_has_error(s->file)) {
+    if (qemu_file_get_error(s->file)) {
         buffered_close(s);
         return;
     }
@@ -249,10 +223,7 @@ static void buffered_rate_tick(void *opaque)
 
     s->bytes_xfer = 0;
 
-    buffered_flush(s);
-
-    /* Add some checks around this */
-    s->put_ready(s->opaque);
+    buffered_put_buffer(s, NULL, 0, 0);
 }
 
 QEMUFile *qemu_fopen_ops_buffered(void *opaque,