cache2 support

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2323 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 204 insertions, 0 deletions

diff --git a/libmpdemux/cache2.c b/libmpdemux/cache2.c
new file mode 100644
index 0000000000..cc13365716
--- /dev/null
+++ b/libmpdemux/cache2.c
@@ -0,0 +1,204 @@
+#ifdef USE_STREAM_CACHE
+// gcc cache2.c ../linux/shmem.o -o cache2
+
+// Initial draft of my new cache system...
+// includes some simulation code, using usleep() to emulate limited bandwith
+// TODO: seeking, data consistency checking
+
+#define READ_SPEED 20
+#define FILL_SPEED 10
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+
+#include "../linux/shmem.h"
+
+#include "stream.h"
+
+int stream_fill_buffer(stream_t *s);
+int stream_seek_long(stream_t *s,off_t pos);
+
+
+typedef struct {
+  // constats:
+  unsigned char *buffer;      // base pointer of the alllocated buffer memory
+  int buffer_size;   // size of the alllocated buffer memory
+  int sector_size;   // size of a single sector (2048/2324)
+     // Note: buffer_size should be N*sector_size, where N is integer...
+  int back_size;  // we should keep back_size amount of old bytes for backward seek
+  int fill_limit; // we should fill buffer if space>fill_limit
+  // reader's pointers:
+  int read_filepos;
+  // filler's pointers:
+  int min_filepos; // buffer contain only a part of the file, from min-max pos
+  int max_filepos;
+  int offset;      // filepos <-> bufferpos  offset value (filepos of the buffer's first byte)
+  // commands/locking:
+  int cmd_lock;   // 1 if we will seek/reset buffer, 2 if we are ready for cmd
+  int fifo_flag;  // 1 if we should use FIFO to notice cache about buffer reads.
+  // callback
+  stream_t* stream;
+} cache_vars_t;
+
+int min_fill=0;
+int sleep_flag=0;
+
+void cache_stats(cache_vars_t* s){
+  int newb=s->max_filepos-s->read_filepos; // new bytes in the buffer
+  printf("0x%06X  [0x%06X]  0x%06X   ",s->min_filepos,s->read_filepos,s->max_filepos);
+  printf("%3d %%  (%3d%%)\n",100*newb/s->buffer_size,100*min_fill/s->buffer_size);
+}
+
+int cache_read(cache_vars_t* s,unsigned char* buf,int size){
+  int total=0;
+  while(size>0){
+    int pos,newb,len;
+    
+    pos=s->read_filepos - s->offset;
+    if(pos<0) pos+=s->buffer_size; else
+    if(pos>=s->buffer_size) pos-=s->buffer_size;
+    
+    newb=s->max_filepos-s->read_filepos; // new bytes in the buffer
+
+    if(newb<min_fill) min_fill=newb; // statistics...
+
+    if(newb<=0){
+	// waiting for buffer fill...
+	usleep(10000); // 10ms
+	continue;
+    }
+    
+//    printf("*** newb: %d bytes ***\n",newb);
+    
+    if(newb>s->buffer_size-pos) newb=s->buffer_size-pos; // handle wrap...
+    if(newb>size) newb=size;
+    
+    // len=write(mem,newb)
+    //printf("Buffer read: %d bytes\n",newb);
+    memcpy(buf,&s->buffer[pos],newb);
+    buf+=newb;
+    len=newb; //usleep(len*READ_SPEED*sleep_flag);
+    // ...
+    
+    s->read_filepos+=len;
+    size-=len;
+    total+=len;
+    
+  }
+  return total;
+}
+
+int cache_fill(cache_vars_t* s){
+  int read,back,newb,space,len,pos,endpos;
+  
+  read=s->read_filepos;
+  
+  // calc number of back-bytes:
+  back=read - s->min_filepos;
+  if(back<0) back=0; // strange...
+  if(back>s->back_size) back=s->back_size;
+  
+  // calc number of new bytes:
+  newb=s->max_filepos - read;
+  if(newb<0) newb=0; // strange...
+
+  // calc free buffer space:
+  space=s->buffer_size - (newb+back);
+  
+  // calc bufferpos:
+  pos=s->max_filepos - s->offset;
+  if(pos>=s->buffer_size) pos-=s->buffer_size; // wrap-around
+  
+  if(space<s->fill_limit){
+//    printf("Buffer is full (%d bytes free, limit: %d)\n",space,s->fill_limit);
+    return 0; // no fill...
+  }
+
+//  printf("### read=0x%X  back=%d  newb=%d  space=%d  pos=%d\n",read,back,newb,space,pos);
+     
+  // reduce space if needed:
+  if(space>s->buffer_size-pos) space=s->buffer_size-pos;
+  
+//  if(space>32768) space=32768; // limit one-time block size
+  if(space>4*s->sector_size) space=4*s->sector_size;
+  
+  s->min_filepos=read-back; // avoid seeking-back to temp area...
+  
+  // ....
+  //printf("Buffer fill: %d bytes of %d\n",space,s->buffer_size);
+  //len=space; usleep(len*FILL_SPEED*sleep_flag);
+  //len=stream_fill_buffer(s->stream);
+  //memcpy(&s->buffer[pos],s->stream->buffer,len); // avoid this extra copy!
+  // ....
+  stream_read(s->stream,&s->buffer[pos],space); len=space;
+  
+  s->max_filepos+=len;
+  if(pos+len>=s->buffer_size){
+      // wrap...
+      s->offset+=s->buffer_size;
+  }
+  
+  return len;
+  
+}
+
+cache_vars_t* cache_init(int size,int sector){
+  int num;
+  cache_vars_t* s=shmem_alloc(sizeof(cache_vars_t));
+  memset(s,0,sizeof(cache_vars_t));
+  num=size/sector;
+  s->buffer_size=num*sector;
+  s->sector_size=sector;
+  s->buffer=shmem_alloc(s->buffer_size);
+  s->fill_limit=8*sector;
+  s->back_size=size/2;
+  return s;
+}
+
+static void exit_sighandler(int x){
+  // close stream
+  exit(0);
+}
+
+void stream_enable_cache(stream_t *s,int size){
+  int ss=(s->type==STREAMTYPE_VCD)?VCD_SECTOR_DATA:STREAM_BUFFER_SIZE;
+  s->cache_data=cache_init(size,ss);
+  ((cache_vars_t*)s->cache_data)->stream=s; // callback
+  if((s->cache_pid=fork())) return; // parent exits
+// cache thread mainloop:
+  signal(SIGTERM,exit_sighandler); // kill
+  while(1){
+    if(!cache_fill(s->cache_data)){
+	 usleep(50000); // idle
+    }
+	 cache_stats(s->cache_data);
+  }
+}
+
+int cache_stream_fill_buffer(stream_t *s){
+  int len;
+  if(s->eof){ s->buf_pos=s->buf_len=0; return 0; }
+  if(!s->cache_pid) return stream_fill_buffer(s);
+
+  len=cache_read(s->cache_data,s->buffer, ((cache_vars_t*)s->cache_data)->sector_size);
+  
+  if(len<=0){ s->eof=1; s->buf_pos=s->buf_len=0; return 0; }
+  s->buf_pos=0;
+  s->buf_len=len;
+  s->pos+=len;
+//  printf("[%d]",len);fflush(stdout);
+  return len;
+
+}
+
+int cache_stream_seek_long(stream_t *s,off_t pos){
+
+  if(!s->cache_pid) return stream_seek_long(s,pos);
+
+  printf("cache2 seek not implemented!!!!!!!!\n");
+  return 0;
+}
+
+#endif