From 3789d48fc4ed515fd4fc879b9cdb2c6ffcc46cad Mon Sep 17 00:00:00 2001
From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Fri, 7 May 2010 18:12:56 +0200
Subject: [PATCH] Use O_DIRECT buffer flushing only when we operate really on
 O_DIRECT file

The flush_buffer function is called also when a tag is written at the
end of the encoding and it operates over DynBufer structure instead of
file.
---
 libavformat/avio.h    |  2 ++
 libavformat/aviobuf.c | 41 +++++++++++++++++++++++++++++++++++------
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/libavformat/avio.h b/libavformat/avio.h
index be02b06f6..b8b35afe8 100644
--- a/libavformat/avio.h
+++ b/libavformat/avio.h
@@ -64,6 +64,7 @@ typedef struct URLPollEntry {
 #define URL_RDONLY 0
 #define URL_WRONLY 1
 #define URL_RDWR   2
+#define URL_DIRECT 4
 
 typedef int URLInterruptCB(void);
 
@@ -197,6 +198,7 @@ typedef struct {
     int must_flush; /**< true if the next seek should flush */
     int eof_reached; /**< true if eof reached */
     int write_flag;  /**< true if open for writing */
+    int o_direct_flag; /**< true if the underlaying file is open with O_DIRECT */
     int is_streamed;
     int max_packet_size;
     unsigned long checksum;
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 04e519916..8493e5532 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -81,7 +81,7 @@ ByteIOContext *av_alloc_put_byte(
 
 #define BLOCK_SIZE 512
 
-static void flush_buffer(ByteIOContext *s)
+static void flush_buffer_o_direct(ByteIOContext *s)
 {
     size_t data_len = s->buf_ptr - s->buffer;
 
@@ -95,7 +95,7 @@ static void flush_buffer(ByteIOContext *s)
     size_t to_write = (data_len + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
     size_t whole_blocks = data_len & ~(BLOCK_SIZE - 1);
     int64_t res = AVERROR(EPIPE);
-    av_log(NULL, AV_LOG_ERROR, "YYY dl=%zd, tw=%zd\n", data_len, to_write);
+    //av_log(NULL, AV_LOG_ERROR, "%p: YYY dl=%zd, tw=%zd\n", s, data_len, to_write);
     if (data_len > 0) {
         if (s->write_packet && !s->error){
             int ret= s->write_packet(s->opaque, s->buffer, to_write);
@@ -116,8 +116,30 @@ static void flush_buffer(ByteIOContext *s)
 	    res = s->seek(s->opaque, s->pos, SEEK_SET);
 	if (res < 0)
 	    av_log(NULL, AV_LOG_ERROR, "seek error inside flush_buffer: %lld\n", res);
-	av_log(NULL, AV_LOG_ERROR, "ZZZ tw=%zu, pos=%zd\n", to_write, s->pos);
+	//av_log(NULL, AV_LOG_ERROR, "ZZZ tw=%zu, pos=%zd\n", to_write, s->pos);
+    }
+}
+
+static void flush_buffer(ByteIOContext *s)
+{
+    if (s->o_direct_flag) {
+	flush_buffer_o_direct(s);
+	return;
+    }
+    if (s->buf_ptr > s->buffer) {
+        if (s->write_packet && !s->error){
+            int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
+            if(ret < 0){
+                s->error = ret;
+            }
+        }
+        if(s->update_checksum){
+            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
+            s->checksum_ptr= s->buffer;
+        }
+        s->pos += s->buf_ptr - s->buffer;
     }
+    s->buf_ptr = s->buffer;
 }
 
 void put_byte(ByteIOContext *s, int b)
@@ -171,13 +193,14 @@ int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
             return offset1;
         offset += offset1;
     }
-    av_log(NULL, AV_LOG_ERROR, "SEEK to %llu\n", offset);
+    av_log(NULL, AV_LOG_ERROR, "%p: SEEK from %llu to %llu\n", s, pos, offset);
 
     offset1 = offset - pos;
     if (!s->must_flush &&
         offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
         /* can do the seek inside the buffer */
         s->buf_ptr = s->buffer + offset1;
+	av_log(NULL, AV_LOG_ERROR, "Internal seek by %llu\n", offset1);
     } else if(s->is_streamed && !s->write_flag &&
               offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
         while(s->pos < offset && !s->eof_reached)
@@ -566,8 +589,14 @@ int url_fdopen(ByteIOContext **s, URLContext *h)
     } else {
         buffer_size = IO_BUFFER_SIZE;
     }
-    buffer_size = 2*buffer_size+BLOCK_SIZE;
-    buffer = memalign(sysconf(_SC_PAGESIZE), buffer_size);
+    (*s)->o_direct_flag = !!(h->flags & URL_DIRECT);
+    if ((*s)->o_direct_flag) {
+	buffer_size = 2*buffer_size+BLOCK_SIZE;
+	buffer = memalign(sysconf(_SC_PAGESIZE), buffer_size);
+	;
+    } else {
+	buffer = av_malloc(buffer_size);
+    }
     if (!buffer)
         return AVERROR(ENOMEM);
 
-- 
2.39.2