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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
commit940b4d1848e8c70ab7642901a68594e8016caffc (patch)
treeeb72f344ee6c3d9b80a7ecc079ea79e9fba8676d /package/source/zipapi/ThreadedDeflater.cxx
parentInitial commit. (diff)
downloadlibreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.tar.xz
libreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.zip
Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'package/source/zipapi/ThreadedDeflater.cxx')
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1 files changed, 220 insertions, 0 deletions
diff --git a/package/source/zipapi/ThreadedDeflater.cxx b/package/source/zipapi/ThreadedDeflater.cxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright
+ * ownership. The ASF licenses this file to you under the Apache
+ * License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <ThreadedDeflater.hxx>
+#include <zlib.h>
+#include <com/sun/star/packages/zip/ZipConstants.hpp>
+#include <sal/log.hxx>
+
+using namespace com::sun::star::packages::zip::ZipConstants;
+using namespace com::sun::star;
+
+namespace ZipUtils
+{
+const sal_Int64 MaxBlockSize = 128 * 1024;
+
+// Parallel ZLIB compression using threads. The class internally splits the data into
+// blocks and spawns ThreadPool tasks to process them independently. This is achieved
+// in a similar way how pigz works, see comments from Mark Adler at
+// https://stackoverflow.com/questions/30294766/how-to-use-multiple-threads-for-zlib-compression
+// and
+// https://stackoverflow.com/questions/30794053/how-to-use-multiple-threads-for-zlib-compression-same-input-source
+
+// Everything here should be either read-only, or writing to distinct data, or atomic.
+
+class ThreadedDeflater::Task : public comphelper::ThreadTask
+{
+ z_stream stream;
+ ThreadedDeflater* deflater;
+ int sequence;
+ int blockSize;
+ bool firstTask : 1;
+ bool lastTask : 1;
+
+public:
+ Task(ThreadedDeflater* deflater_, int sequence_, int blockSize_, bool firstTask_,
+ bool lastTask_)
+ : comphelper::ThreadTask(deflater_->threadTaskTag)
+ , stream()
+ , deflater(deflater_)
+ , sequence(sequence_)
+ , blockSize(blockSize_)
+ , firstTask(firstTask_)
+ , lastTask(lastTask_)
+ {
+ }
+
+private:
+ virtual void doWork() override;
+};
+
+ThreadedDeflater::ThreadedDeflater(sal_Int32 nSetLevel)
+ : threadTaskTag(comphelper::ThreadPool::createThreadTaskTag())
+ , totalIn(0)
+ , totalOut(0)
+ , zlibLevel(nSetLevel)
+{
+}
+
+ThreadedDeflater::~ThreadedDeflater() COVERITY_NOEXCEPT_FALSE { clear(); }
+
+void ThreadedDeflater::deflateWrite(
+ const css::uno::Reference<css::io::XInputStream>& xInStream,
+ std::function<void(const css::uno::Sequence<sal_Int8>&, sal_Int32)> aProcessInputFunc,
+ std::function<void(const css::uno::Sequence<sal_Int8>&, sal_Int32)> aProcessOutputFunc)
+{
+ sal_Int64 nThreadCount = comphelper::ThreadPool::getSharedOptimalPool().getWorkerCount();
+ sal_Int64 batchSize = MaxBlockSize * nThreadCount;
+ inBuffer.realloc(batchSize);
+ prevDataBlock.realloc(MaxBlockSize);
+ outBuffers.resize(nThreadCount);
+ maProcessOutputFunc = aProcessOutputFunc;
+ bool firstTask = true;
+
+ while (xInStream->available() > 0)
+ {
+ sal_Int64 inputBytes = xInStream->readBytes(inBuffer, batchSize);
+ aProcessInputFunc(inBuffer, inputBytes);
+ totalIn += inputBytes;
+ int sequence = 0;
+ bool lastBatch = xInStream->available() <= 0;
+ sal_Int64 bytesPending = inputBytes;
+ while (bytesPending > 0)
+ {
+ sal_Int64 taskSize = std::min(MaxBlockSize, bytesPending);
+ bytesPending -= taskSize;
+ bool lastTask = lastBatch && !bytesPending;
+ comphelper::ThreadPool::getSharedOptimalPool().pushTask(
+ std::make_unique<Task>(this, sequence++, taskSize, firstTask, lastTask));
+
+ if (firstTask)
+ firstTask = false;
+ }
+
+ assert(bytesPending == 0);
+
+ comphelper::ThreadPool::getSharedOptimalPool().waitUntilDone(threadTaskTag);
+
+ if (!lastBatch)
+ {
+ assert(inputBytes == batchSize);
+ std::copy_n(inBuffer.begin() + (batchSize - MaxBlockSize), MaxBlockSize,
+ prevDataBlock.begin());
+ }
+
+ processDeflatedBuffers();
+ }
+}
+
+void ThreadedDeflater::processDeflatedBuffers()
+{
+ sal_Int64 batchOutputSize = 0;
+ for (const auto& buffer : outBuffers)
+ batchOutputSize += buffer.size();
+
+ css::uno::Sequence<sal_Int8> outBuffer(batchOutputSize);
+
+ auto pos = outBuffer.begin();
+ for (auto& buffer : outBuffers)
+ {
+ pos = std::copy(buffer.begin(), buffer.end(), pos);
+ buffer.clear();
+ }
+
+ maProcessOutputFunc(outBuffer, batchOutputSize);
+ totalOut += batchOutputSize;
+}
+
+void ThreadedDeflater::clear()
+{
+ inBuffer = uno::Sequence<sal_Int8>();
+ outBuffers.clear();
+}
+
+#if defined Z_PREFIX
+#define deflateInit2 z_deflateInit2
+#define deflateBound z_deflateBound
+#define deflateSetDictionary z_deflateSetDictionary
+#define deflate z_deflate
+#define deflateEnd z_deflateEnd
+#endif
+
+void ThreadedDeflater::Task::doWork()
+{
+ stream.zalloc = nullptr;
+ stream.zfree = nullptr;
+ stream.opaque = nullptr;
+ // -MAX_WBITS means 32k window size and raw stream
+ if (deflateInit2(&stream, deflater->zlibLevel, Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL,
+ Z_DEFAULT_STRATEGY)
+ != Z_OK)
+ {
+ SAL_WARN("package.threadeddeflate", "deflateInit2() failed");
+ abort();
+ }
+ // Find out size for our output buffer to be large enough for deflate() needing to be called just once.
+ sal_Int64 outputMaxSize = deflateBound(&stream, blockSize);
+ // add extra size for Z_SYNC_FLUSH
+ outputMaxSize += 20;
+ deflater->outBuffers[sequence].resize(outputMaxSize);
+ sal_Int64 myInBufferStart = sequence * MaxBlockSize;
+ // zlib doesn't handle const properly
+ unsigned char* inBufferPtr = reinterpret_cast<unsigned char*>(
+ const_cast<signed char*>(deflater->inBuffer.getConstArray()));
+ if (!firstTask)
+ {
+ // the window size is 32k, so set last 32k of previous data as the dictionary
+ assert(MAX_WBITS == 15);
+ assert(MaxBlockSize >= 32768);
+ if (sequence > 0)
+ {
+ deflateSetDictionary(&stream, inBufferPtr + myInBufferStart - 32768, 32768);
+ }
+ else
+ {
+ unsigned char* prevBufferPtr = reinterpret_cast<unsigned char*>(
+ const_cast<signed char*>(deflater->prevDataBlock.getConstArray()));
+ deflateSetDictionary(&stream, prevBufferPtr + MaxBlockSize - 32768, 32768);
+ }
+ }
+ stream.next_in = inBufferPtr + myInBufferStart;
+ stream.avail_in = blockSize;
+ stream.next_out = reinterpret_cast<unsigned char*>(deflater->outBuffers[sequence].data());
+ stream.avail_out = outputMaxSize;
+
+ // The trick is in using Z_SYNC_FLUSH instead of Z_NO_FLUSH. It will align the data at a byte boundary,
+ // and since we use a raw stream, the data blocks then can be simply concatenated.
+ int res = deflate(&stream, lastTask ? Z_FINISH : Z_SYNC_FLUSH);
+ assert(stream.avail_in == 0); // Check that everything has been deflated.
+ if (lastTask ? res == Z_STREAM_END : res == Z_OK)
+ { // ok
+ sal_Int64 outSize = outputMaxSize - stream.avail_out;
+ deflater->outBuffers[sequence].resize(outSize);
+ }
+ else
+ {
+ SAL_WARN("package.threadeddeflate", "deflate() failed");
+ abort();
+ }
+ deflateEnd(&stream);
+}
+
+} // namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */