Fix #78808: [LMDB] MDB_MAP_FULL: Environment mapsize limit reached

We implement support for a fifth parameter, which allows to specify the
mapsize.  The parameter defaults to zero, in which case the compiled in
default mapsize (usually 1048576) will be used.  The mapsize should be
a multiple of the page size of the OS.

Author: cmb69

NEWS

@@ -13,6 +13,10 @@ PHP                                                                        NEWS
 - Date:
   . Fixed bug #79015 (undefined-behavior in php_date.c). (cmb)
 
+- DBA:
+  . Fixed bug #78808 ([LMDB] MDB_MAP_FULL: Environment mapsize limit reached).
+    (cmb)
+
 - Fileinfo:
   . Fixed bug #74170 (locale information change after mime_content_type).
     (Sergei Turchanov)

UPGRADING

@@ -490,6 +490,12 @@ JSON:
  Curl:
   . libcurl >= 7.15.5 is now required.
 
+ DBA:
+   . As of PHP 7.3.14, dba_open() accepts a fifth optional parameter for lmdb
+     databases which allows to specify the mapsize. The parameter defaults to
+     zero, in which case the compiled in default mapsize (usually 1048576) will
+     be used. The mapsize should be a multiple of the page size of the OS.
+
  Filter:
   . FILTER_VALIDATE_FLOAT now also supports a `thousand` option, which
     defines the set of allowed thousand separator chars.  The default (`"',."`)

ext/dba/dba_lmdb.c

@@ -43,10 +43,18 @@ DBA_OPEN_FUNC(lmdb)
 	MDB_env *env;
 	MDB_txn *txn;
 	int rc, mode = 0644, flags = MDB_NOSUBDIR;
+	zend_long mapsize = 0;
 
 	if(info->argc > 0) {
 		mode = zval_get_long(&info->argv[0]);
 
+		if (info->argc > 1) {
+			mapsize = zval_get_long(&info->argv[1]);
+			if (mapsize < 0) {
+				*error = "mapsize must be greater than or equal to zero";
+				return FAILURE;
+			}
+		}
 		/* TODO implement handling of the additional flags. */
 	}
 
@@ -56,6 +64,14 @@ DBA_OPEN_FUNC(lmdb)
 		return FAILURE;
 	}
 
+	if (mapsize > 0) {
+		rc = mdb_env_set_mapsize(env, (size_t) mapsize);
+		if (rc) {
+			*error = mdb_strerror(rc);
+			return FAILURE;
+		}
+	}
+
 	rc = mdb_env_open(env, info->path, flags, mode);
 	if (rc) {
 		*error = mdb_strerror(rc);

ext/dba/tests/bug78808.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Bug #78808 ([LMDB] MDB_MAP_FULL: Environment mapsize limit reached)
+--SKIPIF--
+<?php
+if (getenv("SKIP_SLOW_TESTS")) die("skip slow test");
+$handler = 'lmdb';
+require_once __DIR__ .'/skipif.inc';
+?>
+--FILE--
+<?php
+$handler = 'lmdb';
+require_once __DIR__ .'/test.inc';
+$lmdb_h = dba_open($db_filename, 'c', 'lmdb', 0644, 5*1048576);
+for ($i = 0; $i < 50000; $i++) {
+    dba_insert('key' . $i, 'value '. $i, $lmdb_h);
+}
+dba_close($lmdb_h);
+echo "done\n";
+?>
+--EXPECT--
+done
+--CLEAN--
+<?php
+require_once dirname(__FILE__) .'/clean.inc';
+?>