utils: Avoid memory merge in gst_util_dump_buffer()

For buffers with multiple memory chunks, gst_buffer_map() has the side
effect of merging the memory chunks into one contiguous
chunk. Since gst_util_dump_mem() used gst_buffer_map() the internals
of the buffer could actually change as a result of printing it.

For the case of a buffer containing several memory chunks,
gst_memory_map() is now used to obtain the memory address and each
memory chunk is dumped separately preceded by a header line. The
behaviour for a buffer containing a single memory chunk is left unchanged.
This commit is contained in:
Johan Sternerup 2019-08-20 17:18:31 +02:00
parent 74797e962f
commit a4d5c95638

View file

@ -48,15 +48,9 @@
#include "glib-compat-private.h"
#include <math.h>
/**
* gst_util_dump_mem:
* @mem: (array length=size): a pointer to the memory to dump
* @size: the size of the memory block to dump
*
* Dumps the memory block into a hex representation. Useful for debugging.
*/
void
gst_util_dump_mem (const guchar * mem, guint size)
static void
gst_util_dump_mem_offset (const guchar * mem, guint size, guint offset)
{
guint i, j;
GString *string = g_string_sized_new (50);
@ -75,7 +69,7 @@ gst_util_dump_mem (const guchar * mem, guint size)
i++;
if (j == 16 || i == size) {
g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j, mem + i - j,
g_print ("%08x (%p): %-48.48s %-16.16s\n", i - j + offset, mem + i - j,
string->str, chars->str);
g_string_set_size (string, 0);
g_string_set_size (chars, 0);
@ -86,6 +80,19 @@ gst_util_dump_mem (const guchar * mem, guint size)
g_string_free (chars, TRUE);
}
/**
* gst_util_dump_mem:
* @mem: (array length=size): a pointer to the memory to dump
* @size: the size of the memory block to dump
*
* Dumps the memory block into a hex representation. Useful for debugging.
*/
void
gst_util_dump_mem (const guchar * mem, guint size)
{
gst_util_dump_mem_offset (mem, size, 0);
}
/**
* gst_util_dump_buffer:
* @buf: a #GstBuffer whose memory to dump
@ -98,10 +105,35 @@ void
gst_util_dump_buffer (GstBuffer * buf)
{
GstMapInfo map;
GstMemory *mem;
guint n_memory;
guint i;
guint offset;
if (gst_buffer_map (buf, &map, GST_MAP_READ)) {
gst_util_dump_mem (map.data, map.size);
gst_buffer_unmap (buf, &map);
n_memory = gst_buffer_n_memory (buf);
if (n_memory == 1) {
if (gst_buffer_map (buf, &map, GST_MAP_READ)) {
gst_util_dump_mem (map.data, map.size);
gst_buffer_unmap (buf, &map);
}
} else if (n_memory > 1) {
/* gst_buffer_map() will merge multiple memory segments into one contiguous
* area so we need to use gst_memory_map() in order not to affect the
* contents of buf */
offset = 0;
for (i = 0; i < n_memory; ++i) {
g_print ("[Memory #%u]\n", i);
mem = gst_buffer_get_memory (buf, i);
if (gst_memory_map (mem, &map, GST_MAP_READ)) {
gst_util_dump_mem_offset (map.data, map.size, offset);
offset += map.size;
gst_memory_unmap (mem, &map);
}
gst_memory_unref (mem);
}
} else {
g_print ("[Empty]\n");
}
}