Started resharding and fixed memory corruption issue.

redis_array.c

@@ -140,6 +140,10 @@ PHP_METHOD(RedisArray, __construct)
 		RETURN_FALSE;
 	}
 
+	// consider previous array as non-existent if empty.
+	if(z_prev && zend_hash_num_elements(Z_ARRVAL_P(z_prev)) == 0)
+		z_prev = NULL;
+
 	if(!z_fun || Z_TYPE_P(z_fun) == IS_NULL) { /* either an array name or a list of hosts */
 		switch(Z_TYPE_P(z0)) {
 			case IS_STRING:
@@ -226,7 +230,7 @@ ra_forward_call(INTERNAL_FUNCTION_PARAMETERS, RedisArray *ra, const char *cmd, i
 		zval_dtor(&z_tmp);
 
 		// add keys to index.
-		ra_index_key(ra, redis_inst, key, key_len);
+		ra_index_key(ra, redis_inst, key, key_len TSRMLS_CC);
 
 		// call EXEC
 		ra_index_exec(ra, redis_inst, return_value);
@@ -341,7 +345,6 @@ PHP_METHOD(RedisArray, _function)
 PHP_METHOD(RedisArray, _rehash)
 {
 	zval *object;
-	int i;
 	RedisArray *ra;
 
 	if (zend_parse_method_parameters(ZEND_NUM_ARGS() TSRMLS_CC, getThis(), "O",

redis_array_impl.c

@@ -212,7 +212,7 @@ ra_find_node(RedisArray *ra, const char *key, int key_len, int *out_pos) {
 
 char *
 ra_find_key(RedisArray *ra, zval *z_args, const char *cmd, int *key_len) {
-	
+
 	zval **zp_tmp;
 	int key_pos = 0; /* TODO: change this depending on the command */
 
@@ -239,23 +239,27 @@ ra_index_multi(RedisArray *ra, zval *z_redis) {
 }
 
 void
-ra_index_key(RedisArray *ra, zval *z_redis, const char *key, int key_len) {
+ra_index_key(RedisArray *ra, zval *z_redis, const char *key, int key_len TSRMLS_DC) {
 
 	int i;
 	zval z_fun_sadd, z_ret, *z_args[2];
-
-	for(i = 0; i < 2; ++i) MAKE_STD_ZVAL(z_args[i]);
+	MAKE_STD_ZVAL(z_args[0]);
+	MAKE_STD_ZVAL(z_args[1]);
 
 	/* prepare args */
-	ZVAL_STRING(&z_fun_sadd, "SADD", 0);
+	ZVAL_STRINGL(&z_fun_sadd, "SADD", 4, 0);
+
 	ZVAL_STRING(z_args[0], PHPREDIS_INDEX_NAME, 0);
 	ZVAL_STRINGL(z_args[1], key, key_len, 1);
 
+
 	/* run SADD */
 	call_user_function(&redis_ce->function_table, &z_redis, &z_fun_sadd, &z_ret, 2, z_args TSRMLS_CC);
-	zval_dtor(&z_ret);
+
+	/* don't dtor z_ret, since we're returning z_redis */
 
 	efree(z_args[0]);
+	efree(z_args[1]);
 }
 
 void
@@ -294,3 +298,86 @@ ra_is_write_cmd(RedisArray *ra, const char *cmd, int cmd_len) {
 	return !ret;
 }
 
+/* list keys from array index */
+static long
+ra_rehash_scan_index(zval *z_redis, char ***keys, int **key_lens) {
+
+	long count, i;
+	zval z_fun_smembers, z_ret, *z_arg, **z_data_pp;
+	HashTable *h_keys;
+	HashPosition pointer;
+
+	/* arg */
+	MAKE_STD_ZVAL(z_arg);
+	ZVAL_STRING(z_arg, PHPREDIS_INDEX_NAME, 0);
+
+	/* run SMEMBERS */
+	ZVAL_STRING(&z_fun_smembers, "SMEMBERS", 0);
+	call_user_function(&redis_ce->function_table, &z_redis, &z_fun_smembers, &z_ret, 1, &z_arg TSRMLS_CC);
+	efree(z_arg);
+	if(Z_TYPE(z_ret) != IS_ARRAY) { /* failure */
+		return -1;	/* TODO: log error. */
+	}
+	h_keys = Z_ARRVAL(z_ret);
+
+	/* allocate key array */
+	count = zend_hash_num_elements(h_keys);
+	*keys = emalloc(count * sizeof(char*));
+	*key_lens = emalloc(count * sizeof(int));
+
+	php_printf("Got %ld keys to redistribute\n", count);
+
+	for (i = 0, zend_hash_internal_pointer_reset_ex(h_keys, &pointer);
+			zend_hash_get_current_data_ex(h_keys, (void**) &z_data_pp, &pointer) == SUCCESS;
+			zend_hash_move_forward_ex(h_keys, &pointer), ++i) {
+
+		(*keys)[i] = emalloc(1 + Z_STRLEN_PP(z_data_pp));
+		(*key_lens)[i] = Z_STRLEN_PP(z_data_pp);
+		(*keys)[i][(*key_lens)[i]] = 0; /* null-terminate string */
+	}
+
+	/* cleanup */
+	zval_dtor(&z_ret);
+
+	return count;
+}
+
+/* list keys using KEYS command */
+static long
+ra_rehash_scan_keys(zval *z_redis, char ***keys, int **key_lens) {
+
+	/* TODO */
+	return 0;
+}
+
+static void
+ra_rehash_server(RedisArray *ra, zval *z_redis, zend_bool b_index) {
+
+	char **keys;
+	int *key_lens;
+	int count;
+
+	/* list all keys */
+	if(b_index) {
+		count = ra_rehash_scan_index(z_redis, &keys, &key_lens);
+	} else {
+		count = ra_rehash_scan_keys(z_redis, &keys, &key_lens);
+	}
+
+	/* for each key, redistribute */
+}
+
+void
+ra_rehash(RedisArray *ra) {
+
+	int i;
+
+	/* redistribute the data, server by server. */
+	if(!ra->prev)
+		return;	/* TODO: compare the two rings for equality */
+
+	for(i = 0; i < ra->prev->count; ++i) {
+		ra_rehash_server(ra, ra->prev->redis[i], ra->index);
+	}
+}
+

redis_array_impl.h

@@ -13,8 +13,10 @@ void ra_init_function_table(RedisArray *ra);
 char * ra_find_key(RedisArray *ra, zval *z_args, const char *cmd, int *key_len);
 void ra_index_multi(RedisArray *ra, zval *z_redis);
 
-void ra_index_key(RedisArray *ra, zval *z_redis, const char *key, int key_len);
+void ra_index_key(RedisArray *ra, zval *z_redis, const char *key, int key_len TSRMLS_DC);
 void ra_index_exec(RedisArray *ra, zval *z_redis, zval *return_value);
 zend_bool ra_is_write_cmd(RedisArray *ra, const char *cmd, int cmd_len);
 
+void ra_rehash(RedisArray *ra);
+
 #endif

tests/array-test.php

@@ -47,4 +47,6 @@ $ra->del(array('a','c'));
 $ra->del('a','c');
 
 var_dump($ra->mget(array('a', 'b', 'c')));
+
+$ra->_rehash();
 ?>