Adding support for archive to handle delayed inserts.

sql/examples/ha_archive.cc:
  Added support for delayed inserts. What delayed inserts mean for archive is that a sync call is not forced with the next select. Instant performance gain, plus if you aren't concerned about having a consistant read you won't be forced to have less then optimized compression.
sql/examples/ha_archive.h:
  Added flags for dalyed inserts and added table flag so that the server knows that archive can support them.

sql/examples/ha_archive.cc

@@ -305,6 +305,7 @@ ARCHIVE_SHARE *ha_archive::get_share(const char *table_name, TABLE *table)
     share->use_count= 0;
     share->table_name_length= length;
     share->table_name= tmp_name;
+    share->delayed= FALSE;
     fn_format(share->data_file_name,table_name,"",ARZ,MY_REPLACE_EXT|MY_UNPACK_FILENAME);
     fn_format(meta_file_name,table_name,"",ARM,MY_REPLACE_EXT|MY_UNPACK_FILENAME);
     strmov(share->table_name,table_name);
@@ -536,7 +537,11 @@ int ha_archive::write_row(byte * buf)
   pthread_mutex_lock(&share->mutex);
   written= gzwrite(share->archive_write, buf, table->reclength);
   DBUG_PRINT("ha_archive::get_row", ("Wrote %d bytes expected %d", written, table->reclength));
-  share->dirty= TRUE;
+  if (!delayed_insert)
+    share->dirty= TRUE;
+  else
+    share->delayed= TRUE;
+
   if (written != table->reclength)
     goto error;
   /*
@@ -594,6 +599,7 @@ int ha_archive::rnd_init(bool scan)
       {
         gzflush(share->archive_write, Z_SYNC_FLUSH);
         share->dirty= FALSE;
+        share->delayed= FALSE;
       }
       pthread_mutex_unlock(&share->mutex);
     }
@@ -628,9 +634,12 @@ int ha_archive::get_row(gzFile file_to_read, byte *buf)
   if (read == 0)
     DBUG_RETURN(HA_ERR_END_OF_FILE);
 
-  /* If the record is the wrong size, the file is probably damaged */
+  /* If the record is the wrong size, the file is probably damaged, unless 
+    we are dealing with a delayed insert. In that case we can assume the file is ok,
+    but our row count doesn't match our data since the file has not been flushed.
+  */
   if ((ulong) read != table->reclength)
-    DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);
+    DBUG_RETURN(share->delayed ? HA_ERR_END_OF_FILE : HA_ERR_CRASHED_ON_USAGE);
 
   /* Calculate blob length, we use this for our buffer */
   for (field=table->blob_field; *field ; field++)
@@ -648,7 +657,7 @@ int ha_archive::get_row(gzFile file_to_read, byte *buf)
     {
       read= gzread(file_to_read, last, size);
       if ((size_t) read != size)
-        DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);
+        DBUG_RETURN(share->delayed ? HA_ERR_END_OF_FILE : HA_ERR_CRASHED_ON_USAGE);
       (*field)->set_ptr(size, last);
       last += size;
     }
@@ -839,6 +848,11 @@ THR_LOCK_DATA **ha_archive::store_lock(THD *thd,
                                        THR_LOCK_DATA **to,
                                        enum thr_lock_type lock_type)
 {
+  if (lock_type == TL_WRITE_DELAYED)
+    delayed_insert= TRUE;
+  else
+    delayed_insert= FALSE;
+
   if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) 
   {
     /* 

sql/examples/ha_archive.h

@@ -32,10 +32,11 @@ typedef struct st_archive_share {
   uint table_name_length,use_count;
   pthread_mutex_t mutex;
   THR_LOCK lock;
-  File meta_file;                   /* Meta file we use */
-  gzFile archive_write;             /* Archive file we are working with */
-  bool dirty;                       /* Flag for if a flush should occur */
-  ulonglong rows_recorded;          /* Number of rows in tables */
+  File meta_file;           /* Meta file we use */
+  gzFile archive_write;     /* Archive file we are working with */
+  bool dirty;               /* Flag for if a flush should occur */
+  ulonglong rows_recorded;  /* Number of rows in tables */
+  bool delayed;             /* If a delayed insert has happened since opena */
 } ARCHIVE_SHARE;
 
 /*
@@ -53,9 +54,10 @@ class ha_archive: public handler
   byte byte_buffer[IO_SIZE]; /* Initial buffer for our string */
   String buffer;             /* Buffer used for blob storage */
   ulonglong scan_rows;       /* Number of rows left in scan */
+  bool delayed_insert;       /* If the insert is delayed */
 
 public:
-  ha_archive(TABLE *table): handler(table)
+  ha_archive(TABLE *table): handler(table), delayed_insert(0)
   {
     /* Set our original buffer from pre-allocated memory */
     buffer.set(byte_buffer, IO_SIZE, system_charset_info);
@@ -72,7 +74,7 @@ public:
   ulong table_flags() const
   {
     return (HA_REC_NOT_IN_SEQ | HA_NOT_EXACT_COUNT | HA_NO_AUTO_INCREMENT |
-            HA_FILE_BASED);
+            HA_FILE_BASED | HA_CAN_INSERT_DELAYED);
   }
   ulong index_flags(uint idx, uint part, bool all_parts) const
   {