validate canons without yatest_common

1 files changed, 326 insertions, 0 deletions

diff --git a/library/cpp/streams/xz/decompress.cpp b/library/cpp/streams/xz/decompress.cpp
new file mode 100644
index 0000000000..361b3cff14
--- /dev/null
+++ b/library/cpp/streams/xz/decompress.cpp
@@ -0,0 +1,326 @@
+#include "decompress.h"
+
+#include <contrib/libs/lzma/liblzma/api/lzma.h>
+
+#include <util/generic/yexception.h>
+#include <util/stream/output.h>
+#include <util/stream/str.h>
+#include <util/stream/zerocopy.h>
+
+// Based on https://fossies.org/linux/xz/doc/examples/02_decompress.c
+
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       02_decompress.c
+/// \brief      Decompress .xz files to stdout
+///
+/// Usage:      ./02_decompress INPUT_FILES... > OUTFILE
+///
+/// Example:    ./02_decompress foo.xz bar.xz > foobar
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+namespace {
+    class IInput {
+    public:
+        virtual ~IInput() = default;
+        virtual size_t Next(const ui8*& ptr) = 0;
+    };
+
+    class TCopyInput: public IInput {
+    public:
+        TCopyInput(IInputStream* slave)
+            : Slave_(slave)
+        {
+        }
+
+        size_t Next(const ui8*& ptr) override {
+            ptr = Inbuf_;
+            return Slave_->Read(Inbuf_, sizeof(Inbuf_));
+        }
+
+    private:
+        IInputStream* Slave_;
+        ui8 Inbuf_[4096];
+    };
+
+    class TZeroCopy: public IInput {
+    public:
+        TZeroCopy(IZeroCopyInput* slave)
+            : Slave_(slave)
+        {
+        }
+
+        size_t Next(const ui8*& ptr) override {
+            return Slave_->Next(&ptr);
+        }
+
+    private:
+        IZeroCopyInput* Slave_;
+    };
+
+    std::unique_ptr<IInput> createInput(IInputStream* slave) {
+        return std::make_unique<TCopyInput>(slave);
+    }
+
+    std::unique_ptr<IInput> createInput(IZeroCopyInput* slave) {
+        return std::make_unique<TZeroCopy>(slave);
+    }
+}
+
+class TUnbufferedXzDecompress::TImpl {
+public:
+    template <class T>
+    TImpl(T* slave)
+        : Input_(createInput(slave))
+        , Strm_(LZMA_STREAM_INIT)
+    {
+        TString err;
+        Y_ENSURE(initDecoder(&Strm_, err),
+                 "Error initializing the decoder: " << err);
+        Strm_.next_in = NULL;
+        Strm_.avail_in = 0;
+    }
+
+    ~TImpl() {
+        // Free the memory allocated for the decoder
+        lzma_end(&Strm_);
+    }
+
+    size_t DoRead(void* buf, size_t len) {
+        if (IsOutFinished_) {
+            return 0;
+        }
+
+        size_t res;
+        TString err;
+
+        Y_ENSURE(decompress(buf, len, res, err),
+                 "lzma decoder error: " << err);
+
+        return res;
+    }
+
+private:
+    bool decompress(void* buf, size_t len, size_t& outLen, TString& err) {
+        // When LZMA_CONCATENATED flag was used when initializing the decoder,
+        // we need to tell lzma_code() when there will be no more input.
+        // This is done by setting action to LZMA_FINISH instead of LZMA_RUN
+        // in the same way as it is done when encoding.
+        //
+        // When LZMA_CONCATENATED isn't used, there is no need to use
+        // LZMA_FINISH to tell when all the input has been read, but it
+        // is still OK to use it if you want. When LZMA_CONCATENATED isn't
+        // used, the decoder will stop after the first .xz stream. In that
+        // case some unused data may be left in strm->next_in.
+        lzma_action action = LZMA_RUN;
+
+        Strm_.next_out = (ui8*)buf;
+        Strm_.avail_out = len;
+
+        while (true) {
+            if (Strm_.avail_in == 0 && !IsInFinished_) {
+                size_t size = Input_->Next(Strm_.next_in);
+
+                if (size == 0) {
+                    IsInFinished_ = true;
+                } else {
+                    Strm_.avail_in = size;
+                }
+
+                // Once the end of the input file has been reached,
+                // we need to tell lzma_code() that no more input
+                // will be coming. As said before, this isn't required
+                // if the LZMA_CONCATENATED flag isn't used when
+                // initializing the decoder.
+                if (IsInFinished_)
+                    action = LZMA_FINISH;
+            }
+
+            lzma_ret ret = lzma_code(&Strm_, action);
+
+            if (ret == LZMA_STREAM_END) {
+                // Once everything has been decoded successfully, the
+                // return value of lzma_code() will be LZMA_STREAM_END.
+                //
+                // It is important to check for LZMA_STREAM_END. Do not
+                // assume that getting ret != LZMA_OK would mean that
+                // everything has gone well or that when you aren't
+                // getting more output it must have successfully
+                // decoded everything.
+                IsOutFinished_ = true;
+            }
+
+            if (Strm_.avail_out == 0 || ret == LZMA_STREAM_END) {
+                outLen = len - Strm_.avail_out;
+                return true;
+            }
+
+            if (ret != LZMA_OK) {
+                // It's not LZMA_OK nor LZMA_STREAM_END,
+                // so it must be an error code. See lzma/base.h
+                // (src/liblzma/api/lzma/base.h in the source package
+                // or e.g. /usr/include/lzma/base.h depending on the
+                // install prefix) for the list and documentation of
+                // possible values. Many values listen in lzma_ret
+                // enumeration aren't possible in this example, but
+                // can be made possible by enabling memory usage limit
+                // or adding flags to the decoder initialization.
+                switch (ret) {
+                    case LZMA_MEM_ERROR:
+                        err = "Memory allocation failed";
+                        break;
+
+                    case LZMA_FORMAT_ERROR:
+                        // .xz magic bytes weren't found.
+                        err = "The input is not in the .xz format";
+                        break;
+
+                    case LZMA_OPTIONS_ERROR:
+                        // For example, the headers specify a filter
+                        // that isn't supported by this liblzma
+                        // version (or it hasn't been enabled when
+                        // building liblzma, but no-one sane does
+                        // that unless building liblzma for an
+                        // embedded system). Upgrading to a newer
+                        // liblzma might help.
+                        //
+                        // Note that it is unlikely that the file has
+                        // accidentally became corrupt if you get this
+                        // error. The integrity of the .xz headers is
+                        // always verified with a CRC32, so
+                        // unintentionally corrupt files can be
+                        // distinguished from unsupported files.
+                        err = "Unsupported compression options";
+                        break;
+
+                    case LZMA_DATA_ERROR:
+                        err = "Compressed file is corrupt";
+                        break;
+
+                    case LZMA_BUF_ERROR:
+                        // Typically this error means that a valid
+                        // file has got truncated, but it might also
+                        // be a damaged part in the file that makes
+                        // the decoder think the file is truncated.
+                        // If you prefer, you can use the same error
+                        // message for this as for LZMA_DATA_ERROR.
+                        err = "Compressed file is truncated or "
+                              "otherwise corrupt";
+                        break;
+
+                    default:
+                        // This is most likely LZMA_PROG_ERROR.
+                        err = "Unknown error, possibly a bug";
+                        break;
+                }
+
+                TStringOutput out(err);
+                out << "[" << (int)ret << "]";
+                return false;
+            }
+        }
+    }
+
+    static bool initDecoder(lzma_stream* strm, TString& err) {
+        // Initialize a .xz decoder. The decoder supports a memory usage limit
+        // and a set of flags.
+        //
+        // The memory usage of the decompressor depends on the settings used
+        // to compress a .xz file. It can vary from less than a megabyte to
+        // a few gigabytes, but in practice (at least for now) it rarely
+        // exceeds 65 MiB because that's how much memory is required to
+        // decompress files created with "xz -9". Settings requiring more
+        // memory take extra effort to use and don't (at least for now)
+        // provide significantly better compression in most cases.
+        //
+        // Memory usage limit is useful if it is important that the
+        // decompressor won't consume gigabytes of memory. The need
+        // for limiting depends on the application. In this example,
+        // no memory usage limiting is used. This is done by setting
+        // the limit to UINT64_MAX.
+        //
+        // The .xz format allows concatenating compressed files as is:
+        //
+        //     echo foo | xz > foobar.xz
+        //     echo bar | xz >> foobar.xz
+        //
+        // When decompressing normal standalone .xz files, LZMA_CONCATENATED
+        // should always be used to support decompression of concatenated
+        // .xz files. If LZMA_CONCATENATED isn't used, the decoder will stop
+        // after the first .xz stream. This can be useful when .xz data has
+        // been embedded inside another file format.
+        //
+        // Flags other than LZMA_CONCATENATED are supported too, and can
+        // be combined with bitwise-or. See lzma/container.h
+        // (src/liblzma/api/lzma/container.h in the source package or e.g.
+        // /usr/include/lzma/container.h depending on the install prefix)
+        // for details.
+        lzma_ret ret = lzma_auto_decoder(
+            strm, UINT64_MAX, LZMA_CONCATENATED);
+
+        // Return successfully if the initialization went fine.
+        if (ret == LZMA_OK)
+            return true;
+
+        // Something went wrong. The possible errors are documented in
+        // lzma/container.h (src/liblzma/api/lzma/container.h in the source
+        // package or e.g. /usr/include/lzma/container.h depending on the
+        // install prefix).
+        //
+        // Note that LZMA_MEMLIMIT_ERROR is never possible here. If you
+        // specify a very tiny limit, the error will be delayed until
+        // the first headers have been parsed by a call to lzma_code().
+        switch (ret) {
+            case LZMA_MEM_ERROR:
+                err = "Memory allocation failed";
+                break;
+
+            case LZMA_OPTIONS_ERROR:
+                err = "Unsupported decompressor flags";
+                break;
+
+            default:
+                // This is most likely LZMA_PROG_ERROR indicating a bug in
+                // this program or in liblzma. It is inconvenient to have a
+                // separate error message for errors that should be impossible
+                // to occur, but knowing the error code is important for
+                // debugging. That's why it is good to print the error code
+                // at least when there is no good error message to show.
+                err = "Unknown error, possibly a bug";
+                break;
+        }
+
+        TStringOutput out(err);
+        out << "[" << (int)ret << "]";
+        return false;
+    }
+
+private:
+    std::unique_ptr<IInput> Input_;
+    lzma_stream Strm_;
+
+    bool IsInFinished_ = false;
+    bool IsOutFinished_ = false;
+};
+
+TUnbufferedXzDecompress::TUnbufferedXzDecompress(IInputStream* slave)
+    : Impl_(std::make_unique<TImpl>(slave))
+{
+}
+
+TUnbufferedXzDecompress::TUnbufferedXzDecompress(IZeroCopyInput* slave)
+    : Impl_(std::make_unique<TImpl>(slave))
+{
+}
+
+TUnbufferedXzDecompress::~TUnbufferedXzDecompress() = default;
+
+size_t TUnbufferedXzDecompress::DoRead(void* buf, size_t len) {
+    return Impl_->DoRead(buf, len);
+}