[FFmpeg-cvslog] avformat/cache: support non continuous caching
Michael Niedermayer
git at videolan.org
Thu Dec 25 19:29:59 CET 2014
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Dec 25 18:48:05 2014 +0100| [0c0168a2104b9f7020e82059121679d302cefa40] | committer: Michael Niedermayer
avformat/cache: support non continuous caching
This allows using the cache protocol on top of seekable but slow protocols to
speed them up
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0c0168a2104b9f7020e82059121679d302cefa40
---
libavformat/cache.c | 166 ++++++++++++++++++++++++++++++++++++++++---------
libavformat/version.h | 2 +-
2 files changed, 138 insertions(+), 30 deletions(-)
diff --git a/libavformat/cache.c b/libavformat/cache.c
index 35f81e8..ef33d17 100644
--- a/libavformat/cache.c
+++ b/libavformat/cache.c
@@ -1,6 +1,6 @@
/*
* Input cache protocol.
- * Copyright (c) 2011 Michael Niedermayer
+ * Copyright (c) 2011,2014 Michael Niedermayer
*
* This file is part of FFmpeg.
*
@@ -23,7 +23,6 @@
/**
* @TODO
- * support non continuous caching
* support keeping files
* support filling with a background thread
*/
@@ -31,6 +30,7 @@
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/file.h"
+#include "libavutil/tree.h"
#include "avformat.h"
#include <fcntl.h>
#if HAVE_IO_H
@@ -44,13 +44,28 @@
#include "os_support.h"
#include "url.h"
+typedef struct CacheEntry {
+ int64_t logical_pos;
+ int64_t physical_pos;
+ int size;
+} CacheEntry;
+
typedef struct Context {
int fd;
+ struct AVTreeNode *root;
+ int64_t logical_pos;
+ int64_t cache_pos;
+ int64_t inner_pos;
int64_t end;
- int64_t pos;
URLContext *inner;
+ int64_t cache_hit, cache_miss;
} Context;
+static int cmp(void *key, const void *node)
+{
+ return (*(int64_t *) key) - ((const CacheEntry *) node)->logical_pos;
+}
+
static int cache_open(URLContext *h, const char *arg, int flags)
{
char *buffername;
@@ -70,26 +85,106 @@ static int cache_open(URLContext *h, const char *arg, int flags)
return ffurl_open(&c->inner, arg, flags, &h->interrupt_callback, NULL);
}
+static int add_entry(URLContext *h, const unsigned char *buf, int size)
+{
+ Context *c= h->priv_data;
+ int64_t pos;
+ int ret;
+ CacheEntry *entry = av_malloc(sizeof(*entry));
+ CacheEntry *entry_ret;
+ struct AVTreeNode *node = av_tree_node_alloc();
+
+ if (!entry || !node) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ //FIXME avoid lseek
+ pos = lseek(c->fd, 0, SEEK_END);
+ if (pos < 0) {
+ ret = AVERROR(errno);
+ av_log(h, AV_LOG_ERROR, "seek in cache failed\n");
+ goto fail;
+ }
+
+ ret = write(c->fd, buf, size);
+ if (ret < 0) {
+ ret = AVERROR(errno);
+ av_log(h, AV_LOG_ERROR, "write in cache failed\n");
+ goto fail;
+ }
+
+ entry->logical_pos = c->logical_pos;
+ entry->physical_pos = pos;
+ entry->size = ret;
+
+ entry_ret = av_tree_insert(&c->root, entry, cmp, &node);
+ if (entry_ret && entry_ret != entry) {
+ ret = -1;
+ av_log(h, AV_LOG_ERROR, "av_tree_insert failed\n");
+ goto fail;
+ }
+ c->cache_pos = entry->physical_pos + entry->size;
+
+ return 0;
+fail:
+ av_free(entry);
+ av_free(node);
+ return ret;
+}
+
static int cache_read(URLContext *h, unsigned char *buf, int size)
{
Context *c= h->priv_data;
+ CacheEntry *entry, *next[2] = {NULL, NULL};
int r;
- if(c->pos<c->end){
- r = read(c->fd, buf, FFMIN(size, c->end - c->pos));
- if(r>0)
- c->pos += r;
- return (-1 == r)?AVERROR(errno):r;
- }else{
- r = ffurl_read(c->inner, buf, size);
- if(r > 0){
- int r2= write(c->fd, buf, r);
- av_assert0(r2==r); // FIXME handle cache failure
- c->pos += r;
- c->end += r;
+ entry = av_tree_find(c->root, &c->logical_pos, cmp, (void**)next);
+
+ if (!entry)
+ entry = next[0];
+
+ if (entry) {
+ int64_t in_block_pos = c->logical_pos - entry->logical_pos;
+ av_assert0(entry->logical_pos <= c->logical_pos);
+ if (in_block_pos < entry->size) {
+ int64_t physical_target = entry->physical_pos + in_block_pos;
+ //FIXME avoid seek if unneeded
+ r = lseek(c->fd, physical_target, SEEK_SET);
+ if (r >= 0)
+ r = read(c->fd, buf, FFMIN(size, entry->size - in_block_pos));
+
+ if (r > 0) {
+ c->logical_pos += r;
+ c->cache_hit ++;
+ return r;
+ }
}
- return r;
}
+
+ // Cache miss or some kind of fault with the cache
+
+ if (c->logical_pos != c->inner_pos) {
+ r = ffurl_seek(c->inner, c->logical_pos, SEEK_SET);
+ if (r<0) {
+ av_log(h, AV_LOG_ERROR, "Failed to perform internal seek\n");
+ return r;
+ }
+ c->inner_pos = r;
+ }
+
+ r = ffurl_read(c->inner, buf, size);
+ if (r<=0)
+ return r;
+ c->inner_pos += r;
+
+ c->cache_miss ++;
+
+ add_entry(h, buf, r);
+ c->logical_pos += r;
+ c->end = FFMAX(c->end, c->logical_pos);
+
+ return r;
}
static int64_t cache_seek(URLContext *h, int64_t pos, int whence)
@@ -100,32 +195,45 @@ static int64_t cache_seek(URLContext *h, int64_t pos, int whence)
pos= ffurl_seek(c->inner, pos, whence);
if(pos <= 0){
pos= ffurl_seek(c->inner, -1, SEEK_END);
- ffurl_seek(c->inner, c->end, SEEK_SET);
- if(pos <= 0)
- return c->end;
+ if (ffurl_seek(c->inner, c->inner_pos, SEEK_SET) < 0)
+ av_log(h, AV_LOG_ERROR, "Inner protocol failed to seekback\n");
}
+ c->end = FFMAX(c->end, pos);
return pos;
}
- pos= lseek(c->fd, pos, whence);
- if(pos<0){
- return pos;
- }else if(pos <= c->end){
- c->pos= pos;
+ if (whence == SEEK_CUR) {
+ whence = SEEK_SET;
+ pos += c->logical_pos;
+ }
+
+ if (whence == SEEK_SET && pos >= 0 && pos < c->end) {
+ //Seems within filesize, assume it will not fail.
+ c->logical_pos = pos;
return pos;
- }else{
- if(lseek(c->fd, c->pos, SEEK_SET) < 0) {
- av_log(h, AV_LOG_ERROR, "Failure to seek in cache\n");
- }
- return AVERROR(EPIPE);
}
+
+ //cache miss
+ pos = lseek(c->fd, pos, whence);
+ if (pos >= 0) {
+ c->logical_pos = pos;
+ c->end = FFMAX(c->end, pos);
+ }
+
+ return pos;
}
static int cache_close(URLContext *h)
{
Context *c= h->priv_data;
+
+ av_log(h, AV_LOG_INFO, "Statistics, cache hits:%"PRId64" cache misses:%"PRId64"\n",
+ c->cache_hit, c->cache_miss);
+
close(c->fd);
ffurl_close(c->inner);
+ av_tree_destroy(c->root);
+
return 0;
}
diff --git a/libavformat/version.h b/libavformat/version.h
index 95d84fe..a4b9a43 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -31,7 +31,7 @@
#define LIBAVFORMAT_VERSION_MAJOR 56
#define LIBAVFORMAT_VERSION_MINOR 16
-#define LIBAVFORMAT_VERSION_MICRO 101
+#define LIBAVFORMAT_VERSION_MICRO 102
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
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