Last patch before push into main tree. Updated from code review and final once over.

A couple of small changes to ha_example (mainly comments). 


sql/examples/ha_archive.cc:
  Changes from Serg.
  A few styles changes, fix for potential hash insert gone wrong, removed bad tables if create fails, gzflush used for flushing by default (had problems with OSX 10.2), and some spelling corrections.
sql/examples/ha_archive.h:
  Removed fast_key_read() and changed the name of a conflicting variable.
sql/examples/ha_example.cc:
  Added a few new comments.
sql/examples/ha_example.h:
  Added pragma interface. Removed fast_key_read() and Serg's request

sql/examples/ha_archive.cc

@@ -29,7 +29,7 @@
   This example was written as a test case for a customer who needed
   a storage engine without indexes that could compress data very well.
   So, welcome to a completely compressed storage engine. This storage
-  engine only does inserts. No replace or updates. All reads are 
+  engine only does inserts. No replace, deletes, or updates. All reads are 
   complete table scans. Compression is done through gzip (bzip compresses
   better, but only marginally, if someone asks I could add support for
   it too, but beaware that it costs a lot more in CPU time then gzip).
@@ -53,7 +53,7 @@
   to be any faster. For writes it is always a bit slower then MyISAM. It has no
   internal limits though for row length.
 
-  Examples between MyISAM and Archive.
+  Examples between MyISAM (packed) and Archive.
 
   Table with 76695844 identical rows:
   29680807 a_archive.ARZ
@@ -75,6 +75,8 @@
    See if during an optimize you can make the table smaller.
    Talk to the gzip guys, come up with a writable format so that updates are doable
      without switching to a block method.
+   Add optional feature so that rows can be flushed at interval (which will cause less
+   compression but may speed up ordered searches).
 
     -Brian
 */
@@ -143,14 +145,14 @@ static ARCHIVE_SHARE *get_share(const char *table_name, TABLE *table)
     share->table_name=tmp_name;
     fn_format(share->data_file_name,table_name,"",ARZ,MY_REPLACE_EXT|MY_UNPACK_FILENAME);
     strmov(share->table_name,table_name);
-    if (my_hash_insert(&archive_open_tables, (byte*) share))
-      goto error;
     /* 
-      It is expensive to open and close the data files and since you can'thave
-      a gzip file that can be both read and written we keep two files open
-      that are shared amoung all open tables.
+      It is expensive to open and close the data files and since you can't have
+      a gzip file that can be both read and written we keep a writer open
+      that is shared amoung all open tables.
     */
-    if ((share->archive_write = gzopen(share->data_file_name, "ab")) == NULL)
+    if ((share->archive_write= gzopen(share->data_file_name, "ab")) == NULL)
+      goto error;
+    if (my_hash_insert(&archive_open_tables, (byte*) share))
       goto error;
     thr_lock_init(&share->lock);
     if (pthread_mutex_init(&share->mutex,MY_MUTEX_INIT_FAST))
@@ -188,7 +190,7 @@ static int free_share(ARCHIVE_SHARE *share)
     pthread_mutex_destroy(&share->mutex);
     my_free((gptr) share, MYF(0));
     if (gzclose(share->archive_write) == Z_ERRNO)
-      rc = -1;
+      rc= -1;
   }
   pthread_mutex_unlock(&archive_mutex);
 
@@ -214,12 +216,15 @@ int ha_archive::open(const char *name, int mode, uint test_if_locked)
 {
   DBUG_ENTER("ha_archive::open");
 
-  if (!(share = get_share(name, table)))
+  if (!(share= get_share(name, table)))
     DBUG_RETURN(1);
   thr_lock_data_init(&share->lock,&lock,NULL);
 
-  if ((archive = gzopen(share->data_file_name, "rb")) == NULL)
+  if ((archive= gzopen(share->data_file_name, "rb")) == NULL)
+  {
+    (void)free_share(share); //We void since we already have an error
     DBUG_RETURN(-1);
+  }
 
   DBUG_RETURN(0);
 }
@@ -227,7 +232,7 @@ int ha_archive::open(const char *name, int mode, uint test_if_locked)
 
 /*
   Closes the file. We first close this storage engines file handle to the
-  archive and then remove our referece count to the table (and possibly
+  archive and then remove our reference count to the table (and possibly
   free it as well).
   */
 int ha_archive::close(void)
@@ -261,23 +266,32 @@ int ha_archive::create(const char *name, TABLE *table_arg, HA_CREATE_INFO *creat
   size_t written;
   DBUG_ENTER("ha_archive::create");
 
-  if ((create_file = my_create(fn_format(name_buff,name,"",ARZ,MY_REPLACE_EXT|MY_UNPACK_FILENAME),0,
+  if ((create_file= my_create(fn_format(name_buff,name,"",ARZ,MY_REPLACE_EXT|MY_UNPACK_FILENAME),0,
                                O_RDWR | O_TRUNC,MYF(MY_WME))) < 0)
     DBUG_RETURN(-1);
-  if ((archive = gzdopen(create_file, "ab")) == NULL)
+  if ((archive= gzdopen(create_file, "ab")) == NULL)
+  {
+    delete_table(name);
     DBUG_RETURN(-1);
-  version = ARCHIVE_VERSION;
-  written = gzwrite(archive, &version, sizeof(version));
+  }
+  version= ARCHIVE_VERSION;
+  written= gzwrite(archive, &version, sizeof(version));
   if (written == 0 || written != sizeof(version))
+  {
+    delete_table(name);
+    DBUG_RETURN(-1);
+  }
+  if (gzclose(archive))
+  {
+    delete_table(name);
     DBUG_RETURN(-1);
-  gzclose(archive);
-  (void)my_close(create_file,MYF(0));
+  }
 
   DBUG_RETURN(0);
 }
 
 /* 
-  Looop at ha_archive::open() for an explanation of the row format.
+  Look at ha_archive::open() for an explanation of the row format.
   Here we just write out the row.
 */
 int ha_archive::write_row(byte * buf)
@@ -289,7 +303,7 @@ int ha_archive::write_row(byte * buf)
   statistic_increment(ha_write_count,&LOCK_status);
   if (table->timestamp_default_now)
     update_timestamp(buf+table->timestamp_default_now-1);
-  written = gzwrite(share->archive_write, buf, table->reclength);
+  written= gzwrite(share->archive_write, buf, table->reclength);
   share->dirty= true;
   if (written == 0 || written != table->reclength)
     DBUG_RETURN(-1);
@@ -300,7 +314,7 @@ int ha_archive::write_row(byte * buf)
     uint32 size= (*field)->get_length();
 
     (*field)->get_ptr(&ptr);
-    written = gzwrite(share->archive_write, ptr, (unsigned)size);
+    written= gzwrite(share->archive_write, ptr, (unsigned)size);
     if (written == 0 || written != size)
       DBUG_RETURN(-1);
   }
@@ -318,10 +332,15 @@ int ha_archive::rnd_init(bool scan)
 {
   DBUG_ENTER("ha_archive::rnd_init");
   int read; // gzread() returns int, and we use this to check the header
+
   /* We rewind the file so that we can read from the beginning if scan */
   if(scan)
+  {
+    records= 0;
     if (gzrewind(archive))
       DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);
+  }
+
   /* 
     If dirty, we lock, and then reset/flush the data.
     I found that just calling gzflush() doesn't always work.
@@ -331,12 +350,17 @@ int ha_archive::rnd_init(bool scan)
     pthread_mutex_lock(&share->mutex);
     if (share->dirty == true)
     {
+/* I was having problems with OSX, but it worked for 10.3 so I am wrapping this with and ifdef */
+#ifdef BROKEN_GZFLUSH
       gzclose(share->archive_write);
-      if ((share->archive_write = gzopen(share->data_file_name, "ab")) == NULL)
+      if ((share->archive_write= gzopen(share->data_file_name, "ab")) == NULL)
       {
         pthread_mutex_unlock(&share->mutex);
         DBUG_RETURN(-1);
       }
+#else
+      gzflush(share->archive_write, Z_SYNC_FLUSH);
+#endif
       share->dirty= false;
     }
     pthread_mutex_unlock(&share->mutex);
@@ -346,10 +370,13 @@ int ha_archive::rnd_init(bool scan)
     At the moment we just check the size of version to make sure the header is 
     intact.
   */
-  read= gzread(archive, &version, sizeof(version));
-  if (read == 0 || read != sizeof(version))
-    DBUG_RETURN(-1);
-  records = 0;
+  if (scan)
+  {
+    read= gzread(archive, &version, sizeof(version));
+    if (read == 0 || read != sizeof(version))
+      DBUG_RETURN(-1);
+  }
+
   DBUG_RETURN(0);
 }
 
@@ -358,14 +385,14 @@ int ha_archive::rnd_init(bool scan)
   This is the method that is used to read a row. It assumes that the row is 
   positioned where you want it.
 */
-int ha_archive::read_row(byte *buf)
+int ha_archive::get_row(byte *buf)
 {
   int read; // Bytes read, gzread() returns int
   char *last;
   size_t total_blob_length= 0;
-  DBUG_ENTER("ha_archive::read_row");
+  DBUG_ENTER("ha_archive::get_row");
 
-  read = gzread(archive, buf, table->reclength);
+  read= gzread(archive, buf, table->reclength);
 
   /* If we read nothing we are at the end of the file */
   if (read == 0)
@@ -381,14 +408,13 @@ int ha_archive::read_row(byte *buf)
 
   /* Adjust our row buffer if we need be */
   buffer.alloc(total_blob_length);
-  last = (char *)buffer.ptr();
+  last= (char *)buffer.ptr();
 
-  /* Loopp through our blobs and read them */
+  /* Loop through our blobs and read them */
   for (Field_blob **field=table->blob_field; *field ; field++)
   {
-    /* Need to setup buffer tomorrow so that it is sued to contain all blobs */
     size_t size= (*field)->get_length();
-    read = gzread(archive, last, size);
+    read= gzread(archive, last, size);
     if (read == 0 || read != size)
       DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);
     (*field)->set_ptr(size, last);
@@ -407,8 +433,8 @@ int ha_archive::rnd_next(byte *buf)
   int rc;
 
   statistic_increment(ha_read_rnd_next_count,&LOCK_status);
-  current_position = gztell(archive);
-  rc = read_row(buf);
+  current_position= gztell(archive);
+  rc= get_row(buf);
   if (!(HA_ERR_END_OF_FILE == rc))
     records++;
 
@@ -438,10 +464,10 @@ int ha_archive::rnd_pos(byte * buf, byte *pos)
 {
   DBUG_ENTER("ha_archive::rnd_pos");
   statistic_increment(ha_read_rnd_count,&LOCK_status);
-  current_position = ha_get_ptr(pos, ref_length);
+  current_position= ha_get_ptr(pos, ref_length);
   z_off_t seek= gzseek(archive, current_position, SEEK_SET);
 
-  DBUG_RETURN(read_row(buf));
+  DBUG_RETURN(get_row(buf));
 }
 
 /******************************************************************************
@@ -511,9 +537,11 @@ int ha_archive::index_last(byte * buf)
 void ha_archive::info(uint flag)
 {
   DBUG_ENTER("ha_archive::info");
+
   /* This is a lie, but you don't want the optimizer to see zero or 1 */
   if (records < 2) 
-    records = 2;
+    records= 2;
+
   DBUG_VOID_RETURN;
 }
 

sql/examples/ha_archive.h

@@ -14,6 +14,10 @@
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
+#ifdef __GNUC__
+#pragma interface			/* gcc class implementation */
+#endif
+
 #include <zlib.h>
 
 /*
@@ -66,7 +70,7 @@ class ha_archive: public handler
   ulong table_flags() const
   {
     return (HA_REC_NOT_IN_SEQ | HA_NOT_EXACT_COUNT | HA_NO_WRITE_DELAYED |
-            HA_NO_AUTO_INCREMENT );
+            HA_NO_AUTO_INCREMENT);
   }
   ulong index_flags(uint inx) const
   {
@@ -83,11 +87,9 @@ class ha_archive: public handler
   /*
     Called in test_quick_select to determine if indexes should be used.
   */
-  virtual double scan_time() { return (double) (records+deleted) / 20.0+10; }
+  virtual double scan_time() { return (double) (records) / 20.0+10; }
   /* The next method will never be called */
   virtual double read_time(ha_rows rows) { return (double) rows /  20.0+1; }
-  virtual bool fast_key_read() { return 1;}
-
   int open(const char *name, int mode, uint test_if_locked);
   int close(void);
   int write_row(byte * buf);
@@ -104,7 +106,7 @@ class ha_archive: public handler
   int rnd_init(bool scan=1);
   int rnd_next(byte *buf);
   int rnd_pos(byte * buf, byte *pos);
-  int ha_archive::read_row(byte *buf);
+  int get_row(byte *buf);
   void position(const byte *record);
   void info(uint);
   int extra(enum ha_extra_function operation);

sql/examples/ha_example.cc

@@ -596,6 +596,10 @@ THR_LOCK_DATA **ha_example::store_lock(THD *thd,
   shared references released. The variable name will just be the name of 
   the table. You will need to remove any files you have created at this point.
 
+  If you do not implement this, the default delete_table() is called from
+  handler.cc and it will delete all files with the file extentions returned
+  by bas_ext().
+
   Called from handler.cc by delete_table and  ha_create_table(). Only used
   during create if the table_flag HA_DROP_BEFORE_CREATE was specified for
   the storage engine.
@@ -610,6 +614,10 @@ int ha_example::delete_table(const char *name)
 /*
   Renames a table from one name to another from alter table call.
 
+  If you do not implement this, the default rename_table() is called from
+  handler.cc and it will delete all files with the file extentions returned
+  by bas_ext().
+
   Called from sql_table.cc by mysql_rename_table().
 */
 int ha_example::rename_table(const char * from, const char * to)

sql/examples/ha_example.h

@@ -21,6 +21,10 @@
   that you can implement.
 */
 
+#ifdef __GNUC__
+#pragma interface			/* gcc class implementation */
+#endif
+
 /*
   EXAMPLE_SHARE is a structure that will be shared amoung all open handlers
   The example implements the minimum of what you will probably need.
@@ -87,7 +91,6 @@ class ha_example: public handler
     The next method will never be called if you do not implement indexes.
   */
   virtual double read_time(ha_rows rows) { return (double) rows /  20.0+1; }
-  virtual bool fast_key_read() { return 1;}
 
   /* 
     Everything below are methods that we implment in ha_example.cc.