X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2FHistoryBlob.php;h=3772926dfdb553d784a5d2d21dcaaabe1004f714;hb=56aa7029b972b19421addc477a81a5c133aae79c;hp=0c44b34415118aa383297fd9f79334024a22d545;hpb=ba2afcd9fa9b1f3f6a865da054068466164fd2fa;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/HistoryBlob.php b/includes/HistoryBlob.php
index 0c44b34415..3772926dfd 100644
--- a/includes/HistoryBlob.php
+++ b/includes/HistoryBlob.php
@@ -1,74 +1,307 @@
 <?php
-/**
- *
- * @package MediaWiki
- */
 
 /**
  * Pure virtual parent
- * @package MediaWiki
+ * @todo document (needs a one-sentence top-level class description, that answers the question: "what is a HistoryBlob?")
  */
-class HistoryBlob
+interface HistoryBlob
 {
-	function setMeta() {}
-	function getMeta() {}
-	function addItem() {}
-	function getItem() {}
+	/**
+	 * setMeta and getMeta currently aren't used for anything, I just thought
+	 * they might be useful in the future.
+	 * @param $meta String: a single string.
+	 */
+	public function setMeta( $meta );
+
+	/**
+	 * setMeta and getMeta currently aren't used for anything, I just thought
+	 * they might be useful in the future.
+	 * Gets the meta-value
+	 */
+	public function getMeta();
+
+	/**
+	 * Adds an item of text, returns a stub object which points to the item.
+	 * You must call setLocation() on the stub object before storing it to the
+	 * database
+	 */
+	public function addItem( $text );
+
+	/**
+	 * Get item by hash
+	 */
+	public function getItem( $hash );
+
+	# Set the "default text"
+	# This concept is an odd property of the current DB schema, whereby each text item has a revision
+	# associated with it. The default text is the text of the associated revision. There may, however,
+	# be other revisions in the same object
+	public function setText( $text );
+
+	/**
+	 * Get default text. This is called from Revision::getRevisionText()
+	 */
+	function getText();
 }
 
 /**
  * The real object
- * @package MediaWiki
+ * @todo document (needs one-sentence top-level class description + function descriptions).
  */
-class ConcatenatedGzipHistoryBlob
+class ConcatenatedGzipHistoryBlob implements HistoryBlob
 {
-	/* private */ var $mVersion = 0, $mCompressed = false, $mItems = array();
+	public $mVersion = 0, $mCompressed = false, $mItems = array(), $mDefaultHash = '';
+	public $mFast = 0, $mSize = 0;
 
-	function HistoryBlob() {
+	/** Constructor */
+	public function ConcatenatedGzipHistoryBlob() {
 		if ( !function_exists( 'gzdeflate' ) ) {
-			die( "Need zlib support to read or write this kind of history object (ConcatenatedGzipHistoryBlob)\n" );
+			throw new MWException( "Need zlib support to read or write this kind of history object (ConcatenatedGzipHistoryBlob)\n" );
 		}
 	}
-	
-	function setMeta( $metaData ) {
+
+	#
+	# HistoryBlob implementation:
+	#
+
+	/** @todo document */
+	public function setMeta( $metaData ) {
 		$this->uncompress();
 		$this->mItems['meta'] = $metaData;
 	}
 
-	function getMeta() {
+	/** @todo document */
+	public function getMeta() {
 		$this->uncompress();
 		return $this->mItems['meta'];
 	}
-	
-	function addItem( $text ) {
+
+	/** @todo document */
+	public function addItem( $text ) {
 		$this->uncompress();
-		$this->mItems[md5($text)] = $text;
+		$hash = md5( $text );
+		$this->mItems[$hash] = $text;
+		$this->mSize += strlen( $text );
+
+		$stub = new HistoryBlobStub( $hash );
+		return $stub;
 	}
 
-	function getItem( $hash ) {
-		$this->compress();
-		return $this->mItems[$hash];
+	/** @todo document */
+	public function getItem( $hash ) {
+		$this->uncompress();
+		if ( array_key_exists( $hash, $this->mItems ) ) {
+			return $this->mItems[$hash];
+		} else {
+			return false;
+		}
+	}
+
+	/** @todo document */
+	public function setText( $text ) {
+		$this->uncompress();
+		$stub = $this->addItem( $text );
+		$this->mDefaultHash = $stub->mHash;
 	}
 
-	function compress() {
+	/** @todo document */
+	public function getText() {
+		$this->uncompress();
+		return $this->getItem( $this->mDefaultHash );
+	}
+
+	# HistoryBlob implemented.
+
+
+	/** @todo document */
+	public function removeItem( $hash ) {
+		$this->mSize -= strlen( $this->mItems[$hash] );
+		unset( $this->mItems[$hash] );
+	}
+
+	/** @todo document */
+	public function compress() {
 		if ( !$this->mCompressed  ) {
 			$this->mItems = gzdeflate( serialize( $this->mItems ) );
 			$this->mCompressed = true;
 		}
 	}
 
-	function uncompress() { 
+	/** @todo document */
+	public function uncompress() {
 		if ( $this->mCompressed ) {
 			$this->mItems = unserialize( gzinflate( $this->mItems ) );
+			$this->mCompressed = false;
 		}
 	}
 
+
+	/** @todo document */
 	function __sleep() {
-		compress();
+		$this->compress();
+		return array( 'mVersion', 'mCompressed', 'mItems', 'mDefaultHash' );
 	}
 
+	/** @todo document */
 	function __wakeup() {
-		uncompress();
+		$this->uncompress();
+	}
+
+	/**
+	 * Determines if this object is happy
+	 */
+	public function isHappy( $maxFactor, $factorThreshold ) {
+		if ( count( $this->mItems ) == 0 ) {
+			return true;
+		}
+		if ( !$this->mFast ) {
+			$this->uncompress();
+			$record = serialize( $this->mItems );
+			$size = strlen( $record );
+			$avgUncompressed = $size / count( $this->mItems );
+			$compressed = strlen( gzdeflate( $record ) );
+
+			if ( $compressed < $factorThreshold * 1024 ) {
+				return true;
+			} else {
+				return $avgUncompressed * $maxFactor < $compressed;
+			}
+		} else {
+			return count( $this->mItems ) <= 10;
+		}
+	}
+}
+
+
+/**
+ * One-step cache variable to hold base blobs; operations that
+ * pull multiple revisions may often pull multiple times from
+ * the same blob. By keeping the last-used one open, we avoid
+ * redundant unserialization and decompression overhead.
+ */
+global $wgBlobCache;
+$wgBlobCache = array();
+
+
+/**
+ * @todo document (needs one-sentence top-level class description + some function descriptions).
+ */
+class HistoryBlobStub {
+	var $mOldId, $mHash, $mRef;
+
+	/** @todo document */
+	function HistoryBlobStub( $hash = '', $oldid = 0 ) {
+		$this->mHash = $hash;
+	}
+
+	/**
+	 * Sets the location (old_id) of the main object to which this object
+	 * points
+	 */
+	function setLocation( $id ) {
+		$this->mOldId = $id;
+	}
+
+	/**
+	 * Sets the location (old_id) of the referring object
+	 */
+	function setReferrer( $id ) {
+		$this->mRef = $id;
+	}
+
+	/**
+	 * Gets the location of the referring object
+	 */
+	function getReferrer() {
+		return $this->mRef;
+	}
+
+	/** @todo document */
+	function getText() {
+		$fname = 'HistoryBlobStub::getText';
+		global $wgBlobCache;
+		if( isset( $wgBlobCache[$this->mOldId] ) ) {
+			$obj = $wgBlobCache[$this->mOldId];
+		} else {
+			$dbr = wfGetDB( DB_SLAVE );
+			$row = $dbr->selectRow( 'text', array( 'old_flags', 'old_text' ), array( 'old_id' => $this->mOldId ) );
+			if( !$row ) {
+				return false;
+			}
+			$flags = explode( ',', $row->old_flags );
+			if( in_array( 'external', $flags ) ) {
+				$url=$row->old_text;
+				@list( /* $proto */ ,$path)=explode('://',$url,2);
+				if ($path=="") {
+					wfProfileOut( $fname );
+					return false;
+				}
+				$row->old_text=ExternalStore::fetchFromUrl($url);
+
+			}
+			if( !in_array( 'object', $flags ) ) {
+				return false;
+			}
+
+			if( in_array( 'gzip', $flags ) ) {
+				// This shouldn't happen, but a bug in the compress script
+				// may at times gzip-compress a HistoryBlob object row.
+				$obj = unserialize( gzinflate( $row->old_text ) );
+			} else {
+				$obj = unserialize( $row->old_text );
+			}
+
+			if( !is_object( $obj ) ) {
+				// Correct for old double-serialization bug.
+				$obj = unserialize( $obj );
+			}
+
+			// Save this item for reference; if pulling many
+			// items in a row we'll likely use it again.
+			$obj->uncompress();
+			$wgBlobCache = array( $this->mOldId => $obj );
+		}
+		return $obj->getItem( $this->mHash );
+	}
+
+	/** @todo document */
+	function getHash() {
+		return $this->mHash;
+	}
+}
+
+
+/**
+ * To speed up conversion from 1.4 to 1.5 schema, text rows can refer to the
+ * leftover cur table as the backend. This avoids expensively copying hundreds
+ * of megabytes of data during the conversion downtime.
+ *
+ * Serialized HistoryBlobCurStub objects will be inserted into the text table
+ * on conversion if $wgFastSchemaUpgrades is set to true.
+ */
+class HistoryBlobCurStub {
+	var $mCurId;
+
+	/** @todo document */
+	function HistoryBlobCurStub( $curid = 0 ) {
+		$this->mCurId = $curid;
+	}
+
+	/**
+	 * Sets the location (cur_id) of the main object to which this object
+	 * points
+	 */
+	function setLocation( $id ) {
+		$this->mCurId = $id;
+	}
+
+	/** @todo document */
+	function getText() {
+		$dbr = wfGetDB( DB_SLAVE );
+		$row = $dbr->selectRow( 'cur', array( 'cur_text' ), array( 'cur_id' => $this->mCurId ) );
+		if( !$row ) {
+			return false;
+		}
+		return $row->cur_text;
 	}
 }
-?>