more work on IO_CACHE

portability fixes for systems with broken syscalls that do not interrupt on 
a signal
temporary commit - will not be pushed, need to sync up


include/my_sys.h:
  work on READ_APPEND cache
mysys/Makefile.am:
  change to test IO_CACHE
mysys/mf_iocache.c:
  work on READ_APPEND cache
BitKeeper/etc/ignore:
  Added mysys/#mf_iocache.c# mysys/test_io_cache to the ignore list
sql/mysqld.cc:
  make shutdown work on broken systems
sql/sql_repl.cc:
  make sure slave can be stopped on broken systems in all cases, clean-up

1 files changed, 195 insertions, 22 deletions

diff --git a/mysys/mf_iocache.c b/mysys/mf_iocache.c
index f0100b5122b..d18c3a51c5d 100644
--- a/mysys/mf_iocache.c
+++ b/mysys/mf_iocache.c
@@ -41,6 +41,10 @@ static void my_aiowait(my_aio_result *result);
 #include <assert.h>
 #include <errno.h>
 
+#ifdef MAIN
+#include <my_dir.h>
+#endif
+
 static void init_read_function(IO_CACHE* info, enum cache_type type);
 
 static void init_read_function(IO_CACHE* info, enum cache_type type)
@@ -152,7 +156,7 @@ int init_io_cache(IO_CACHE *info, File file, uint cachesize,
   info->rc_request_pos=info->rc_pos=info->buffer;
   if (type == SEQ_READ_APPEND)
   {
-    info->append_pos = info->append_buffer;
+    info->append_read_pos = info->append_write_pos = info->append_buffer;
     info->append_end = info->append_buffer + info->buffer_length;
 #ifdef THREAD    
     pthread_mutex_init(&info->append_buffer_lock,MY_MUTEX_INIT_FAST);
@@ -277,6 +281,10 @@ my_bool reinit_io_cache(IO_CACHE *info, enum cache_type type,
 			  ~(my_off_t) 0);
     }
   }
+  if (info->type == SEQ_READ_APPEND)
+  {
+    info->append_read_pos = info->append_write_pos = info->append_buffer;
+  }
   info->type=type;
   info->error=0;
   init_read_function(info,type);
@@ -294,7 +302,7 @@ my_bool reinit_io_cache(IO_CACHE *info, enum cache_type type,
   info->inited=0;
 #endif
   DBUG_RETURN(0);
-} /* init_io_cache */
+} /* reinit_io_cache */
 
 
 
@@ -377,11 +385,19 @@ int _my_b_read(register IO_CACHE *info, byte *Buffer, uint Count)
   return 0;
 }
 
+/* Do sequential read from the SEQ_READ_APPEND cache
+   we do this in three stages:
+    - first read from info->buffer
+    - then if there are still data to read, try the file descriptor
+    - afterwards, if there are still data to read, try append buffer
+*/
+
 int _my_b_seq_read(register IO_CACHE *info, byte *Buffer, uint Count)
 {
-  uint length,diff_length,left_length;
+  uint length,diff_length,left_length,save_count;
   my_off_t max_length, pos_in_file;
-  
+  save_count=Count;
+  /* first, read the regular buffer */
   if ((left_length=(uint) (info->rc_end-info->rc_pos)))
   {
     dbug_assert(Count >= left_length);	/* User is not using my_b_read() */
@@ -390,30 +406,33 @@ int _my_b_seq_read(register IO_CACHE *info, byte *Buffer, uint Count)
     Count-=left_length;
   }
   /* pos_in_file always point on where info->buffer was read */
-  pos_in_file=info->pos_in_file+(uint) (info->rc_end - info->buffer);
+  if ((pos_in_file=info->pos_in_file+(uint) (info->rc_end - info->buffer)) >=
+      info->end_of_file)
+  {
+    info->pos_in_file=pos_in_file;
+    goto read_append_buffer;
+  }
   /* no need to seek since the read is guaranteed to be sequential */
   diff_length=(uint) (pos_in_file & (IO_SIZE-1));
-#ifdef THREAD
-  pthread_mutex_lock(&info->append_buffer_lock);
-#endif  
-#ifdef THREAD
-  pthread_mutex_unlock(&info->append_buffer_lock);
-#endif  
+  
+  /* now the second stage begins - read from file descriptor */
   if (Count >= (uint) (IO_SIZE+(IO_SIZE-diff_length)))
   {					/* Fill first intern buffer */
     uint read_length;
     if (info->end_of_file == pos_in_file)
     {					/* End of file */
-      info->error=(int) left_length;
-      return 1;
+      goto read_append_buffer;
     }
     length=(Count & (uint) ~(IO_SIZE-1))-diff_length;
     if ((read_length=my_read(info->file,Buffer,(uint) length,info->myflags))
 	!= (uint) length)
     {
-      info->error= read_length == (uint) -1 ? -1 :
-	(int) (read_length+left_length);
-      return 1;
+      if (read_length != (uint)-1)
+      {
+	Count -= read_length;
+	Buffer += read_length;
+      }
+      goto read_append_buffer;
     }
     Count-=length;
     Buffer+=length;
@@ -422,15 +441,13 @@ int _my_b_seq_read(register IO_CACHE *info, byte *Buffer, uint Count)
     diff_length=0;
   }
   max_length=info->read_length-diff_length;
-  if (info->type != READ_FIFO &&
-      (info->end_of_file - pos_in_file) < max_length)
+  if ((info->end_of_file - pos_in_file) < max_length)
     max_length = info->end_of_file - pos_in_file;
   if (!max_length)
   {
     if (Count)
     {
-      info->error= left_length;		/* We only got this many char */
-      return 1;
+      goto read_append_buffer;
     }
     length=0;				/* Didn't read any chars */
   }
@@ -439,15 +456,36 @@ int _my_b_seq_read(register IO_CACHE *info, byte *Buffer, uint Count)
 	   length == (uint) -1)
   {
     if (length != (uint) -1)
+    {
       memcpy(Buffer,info->buffer,(size_t) length);
-    info->error= length == (uint) -1 ? -1 : (int) (length+left_length);
-    return 1;
+      Count -= length;
+      Buffer += length;
+    }
+    goto read_append_buffer;
   }
   info->rc_pos=info->buffer+Count;
   info->rc_end=info->buffer+length;
   info->pos_in_file=pos_in_file;
   memcpy(Buffer,info->buffer,(size_t) Count);
   return 0;
+read_append_buffer:
+  lock_append_buffer(info);
+  if (!Count) return 0;
+  {
+    uint copy_len = (uint)(info->append_read_pos -
+			   info->append_write_pos);
+    dbug_assert(info->append_read_pos <= info->append_write_pos);
+    if (copy_len > Count)
+      copy_len = Count;
+    memcpy(Buffer, info->append_read_pos,
+	 copy_len);
+    info->append_read_pos += copy_len;
+    Count -= copy_len;
+    if (Count)
+      info->error = save_count - Count; 
+  }
+  unlock_append_buffer(info);
+  return Count ? 1 : 0;
 }
 
 #ifdef HAVE_AIOWAIT
@@ -672,6 +710,31 @@ int _my_b_write(register IO_CACHE *info, const byte *Buffer, uint Count)
   return 0;
 }
 
+int _my_b_append(register IO_CACHE *info, const byte *Buffer, uint Count)
+{
+  uint rest_length,length;
+
+  rest_length=(uint) (info->append_end -
+		      info->append_write_pos);
+  memcpy(info->append_write_pos,Buffer,(size_t) rest_length);
+  Buffer+=rest_length;
+  Count-=rest_length;
+  info->append_write_pos+=rest_length;
+  if (flush_io_cache(info))
+    return 1;
+  if (Count >= IO_SIZE)
+  {					/* Fill first intern buffer */
+    length=Count & (uint) ~(IO_SIZE-1);
+    if (my_write(info->file,Buffer,(uint) length,info->myflags | MY_NABP))
+      return info->error= -1;
+    Count-=length;
+    Buffer+=length;
+  }
+  memcpy(info->append_write_pos,Buffer,(size_t) Count);
+  info->append_write_pos+=Count;
+  return 0;
+}
+
 
 /*
   Write a block to disk where part of the data may be inside the record
@@ -756,6 +819,30 @@ int flush_io_cache(IO_CACHE *info)
       DBUG_RETURN(0);
     }
   }
+  else if (info->type == SEQ_READ_APPEND)
+  {
+    if (info->file == -1)
+    {
+      if (real_open_cached_file(info))
+	DBUG_RETURN((info->error= -1));
+    }
+    lock_append_buffer(info);
+    if (info->append_write_pos != info->append_buffer)
+    {
+      length=(uint) (info->append_write_pos - info->append_buffer);
+      info->append_read_pos=info->append_write_pos=info->append_buffer;
+      info->append_end=(info->append_buffer+info->buffer_length-
+		    (info->pos_in_file & (IO_SIZE-1)));
+      if (my_write(info->file,info->buffer,length,info->myflags | MY_NABP))
+      {
+	unlock_append_buffer(info);
+	DBUG_RETURN((info->error= -1));
+      }
+      unlock_append_buffer(info);
+      DBUG_RETURN(0);
+    }
+    unlock_append_buffer(info);
+  }
 #ifdef HAVE_AIOWAIT
   else if (info->type != READ_NET)
   {
@@ -784,3 +871,89 @@ int end_io_cache(IO_CACHE *info)
   DBUG_RETURN(error);
 } /* end_io_cache */
 
+#ifdef MAIN
+void die(const char* fmt, ...)
+{
+  va_list va_args;
+  va_start(va_args,fmt);
+  fprintf(stderr,"Error:");
+  vfprintf(stderr, fmt,va_args);
+  fprintf(stderr,", errno=%d\n", errno);
+  exit(1);
+}
+
+int open_file(const char* fname, IO_CACHE* info, int cache_size)
+{
+  int fd;
+  if ((fd=my_open(fname,O_CREAT|O_APPEND|O_RDWR,MYF(MY_WME))) < 0)
+    die("Could not open %s", fname);
+  if (init_io_cache(info, fd, cache_size, SEQ_READ_APPEND, 0,0,MYF(MY_WME)))
+    die("failed in init_io_cache()");
+  return fd;
+}
+
+void close_file(IO_CACHE* info)
+{
+  end_io_cache(info);
+  my_close(info->file, MYF(MY_WME));
+}
+
+int main(int argc, char** argv)
+{
+  IO_CACHE sra_cache; /* SEQ_READ_APPEND */
+  MY_STAT status;
+  const char* fname="/tmp/iocache.test";
+  int cache_size=16384;
+  char llstr_buf[22];
+  int max_block,total_bytes=0;
+  int i,num_loops=100,error=0;
+  char *p;
+  char* block, *block_end;
+  MY_INIT(argv[0]);
+  max_block = cache_size*3;
+  if (!(block=(char*)my_malloc(max_block,MYF(MY_WME))))
+    die("Not enough memory to allocate test block");
+  block_end = block + max_block;
+  for (p = block,i=0; p < block_end;i++)
+  {
+    *p++ = (char)i;
+  }
+  if (my_stat(fname,&status, MYF(0)) &&
+      my_delete(fname,MYF(MY_WME)))
+    {
+      die("Delete of %s failed, aborting", fname);
+    }
+  open_file(fname,&sra_cache, cache_size);
+  for (i = 0; i < num_loops; i++)
+  {
+    char buf[4];
+    int block_size = abs(rand() % max_block);
+    int4store(buf, block_size);
+    if (my_b_write(&sra_cache,buf,4) ||
+	my_b_write(&sra_cache, block, block_size))
+      die("write failed");
+    total_bytes += 4+block_size;
+  }
+  close_file(&sra_cache);
+  my_free(block,MYF(MY_WME));
+  if (!my_stat(fname,&status,MYF(MY_WME)))
+    die("%s failed to stat, but I had just closed it,\
+ wonder how that happened");
+  printf("Final size of %s is %s, wrote %d bytes\n",fname,
+	 llstr(status.st_size,llstr_buf),
+	 total_bytes);
+  my_delete(fname, MYF(MY_WME));
+  /* check correctness of tests */
+  if (total_bytes != status.st_size)
+  {
+    fprintf(stderr,"Not the same number of bytes acutally  in file as bytes \
+supposedly written\n");
+    error=1;
+  }
+  exit(error);
+  return 0;
+}
+#endif
+
+
+