Attachment 37770 Details for Bug 64322 – Performance fix for OLE2 files with a large number of small entries

[patch] Performance fix for OLE2 files with a large number of small entries

poi-performance-fix-for-OLE2-files-with-large-number-small-entries.patch (text/plain), 5.13 KB, created by sits on 2021-03-14 22:35:17 UTC

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Creator: sits

Created: 2021-03-14 22:35:17 UTC

Size: 5.13 KB

patch

obsolete

>Index: poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java
>IDEA additional info:
>Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
><+>UTF-8
>===================================================================
>--- poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java	(revision cee9eb7e2b487c4b451bd167e07e6309835a943b)
>+++ poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java	(date 1615423514626)
>@@ -64,20 +64,25 @@
>        int bigBlockOffset = byteOffset % _filesystem.getBigBlockSize();
> 
>        // Now locate the data block for it
>-       Iterator<ByteBuffer> it = _mini_stream.getBlockIterator();
>+       Iterator<Integer> it = _mini_stream.getBlockOffsetIterator();
>        for(int i=0; i<bigBlockNumber; i++) {
>           it.next();
>        }
>-       ByteBuffer dataBlock = it.next();
>-       assert(dataBlock != null);
>+
>+       try {
>+           ByteBuffer dataBlock = _filesystem.getBlockAt(it.next());
>+           assert(dataBlock != null);
> 
>-       // Position ourselves, and take a slice
>-       dataBlock.position(
>-             dataBlock.position() + bigBlockOffset
>-       );
>-       ByteBuffer miniBuffer = dataBlock.slice();
>-       miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE);
>-       return miniBuffer;
>+           // Position ourselves, and take a slice
>+           dataBlock.position(
>+                   dataBlock.position() + bigBlockOffset
>+           );
>+           ByteBuffer miniBuffer = dataBlock.slice();
>+           miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE);
>+           return miniBuffer;
>+       } catch (IOException e) {
>+          throw new RuntimeException(e);
>+       }
>     }
> 
>     /**
>Index: poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java
>IDEA additional info:
>Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
><+>UTF-8
>===================================================================
>--- poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java	(revision cee9eb7e2b487c4b451bd167e07e6309835a943b)
>+++ poi/poi/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java	(date 1615264885529)
>@@ -96,6 +96,15 @@
>       return new StreamBlockByteBufferIterator(startBlock);
>    }
> 
>+   Iterator<Integer> getBlockOffsetIterator() {
>+      if(startBlock == POIFSConstants.END_OF_CHAIN) {
>+         throw new IllegalStateException(
>+               "Can't read from a new stream before it has been written to"
>+         );
>+      }
>+      return new StreamBlockOffsetIterator(startBlock);
>+   }
>+
>    /**
>     * Updates the contents of the stream to the new
>     *  set of bytes.
>@@ -140,11 +149,11 @@
>    /**
>     * Class that handles a streaming read of one stream
>     */
>-   private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> {
>+   private class StreamBlockOffsetIterator implements Iterator<Integer> {
>       private final ChainLoopDetector loopDetector;
>       private int nextBlock;
> 
>-      StreamBlockByteBufferIterator(int firstBlock) {
>+       StreamBlockOffsetIterator(int firstBlock) {
>          this.nextBlock = firstBlock;
>          try {
>             this.loopDetector = blockStore.getChainLoopDetector();
>@@ -157,26 +166,54 @@
>           return nextBlock != POIFSConstants.END_OF_CHAIN;
>       }
> 
>-      public ByteBuffer next() {
>+      public Integer next() {
>          if (!hasNext()) {
>             throw new NoSuchElementException("Can't read past the end of the stream");
>          }
> 
>-         try {
>-            loopDetector.claim(nextBlock);
>-            ByteBuffer data = blockStore.getBlockAt(nextBlock);
>-            nextBlock = blockStore.getNextBlock(nextBlock);
>-            return data;
>-         } catch(IOException e) {
>-            throw new RuntimeException(e);
>-         }
>-      }
>+          loopDetector.claim(nextBlock);
>+          int currentBlock = nextBlock;
>+          nextBlock = blockStore.getNextBlock(nextBlock);
>+          return currentBlock;
>+      }
>+
>+      public void remove() {
>+         throw new UnsupportedOperationException();
>+      }
>+   }
>+
>+    /**
>+     * Class that handles a streaming read of one stream
>+     */
>+    private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> {
>+        private final StreamBlockOffsetIterator offsetIterator;
>+
>+        StreamBlockByteBufferIterator(int firstBlock) {
>+            offsetIterator = new StreamBlockOffsetIterator(firstBlock);
>+        }
>+
>+        public boolean hasNext() {
>+            return offsetIterator.hasNext();
>+        }
>+
>+        public ByteBuffer next() {
>+            if (!hasNext()) {
>+                throw new NoSuchElementException("Can't read past the end of the stream");
>+            }
>+
>+            try {
>+                return blockStore.getBlockAt(offsetIterator.next());
>+            } catch(IOException e) {
>+                throw new RuntimeException(e);
>+            }
>+        }
> 
>-      public void remove() {
>-         throw new UnsupportedOperationException();
>-      }
>-   }
>+        public void remove() {
>+            throw new UnsupportedOperationException();
>+        }
>+    }
> 
>+
>    protected class StreamBlockByteBuffer extends OutputStream {
>        byte[] oneByte = new byte[1];
>        ByteBuffer buffer;

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Attachments on bug 64322: 37154 | 37155 | 37156 | 37770