bz2_stream.cpp

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#include "rosbag/chunked_file.h"

#include <iostream>
#include <cstring>
#include "console_bridge/console.h"

using std::string;

namespace rosbag {

BZ2Stream::BZ2Stream(ChunkedFile* file) :
    Stream(file),
    verbosity_(0),
    block_size_100k_(9),
    work_factor_(30),
    bzfile_(NULL),
    bzerror_(0)
{ }

CompressionType BZ2Stream::getCompressionType() const {
    return compression::BZ2;
}

void BZ2Stream::startWrite() {
    bzfile_ = BZ2_bzWriteOpen(&bzerror_, getFilePointer(), block_size_100k_, verbosity_, work_factor_);

    switch (bzerror_) {
        case BZ_OK: break;
        default: {
            BZ2_bzWriteClose(&bzerror_, bzfile_, 0, NULL, NULL);
            throw BagException("Error opening file for writing compressed stream");
        }
    }

    setCompressedIn(0);
}

void BZ2Stream::write(void* ptr, size_t size) {
    if (!bzfile_) {
        throw BagException("cannot write to unopened bzfile");
    }

    BZ2_bzWrite(&bzerror_, bzfile_, ptr, size);

    switch (bzerror_) {
    case BZ_IO_ERROR: throw BagException("BZ_IO_ERROR: error writing the compressed file");
    }

    setCompressedIn(getCompressedIn() + size);
}

void BZ2Stream::stopWrite() {
    if (!bzfile_) {
        throw BagException("cannot close unopened bzfile");
    }

    unsigned int nbytes_in;
    unsigned int nbytes_out;
    BZ2_bzWriteClose(&bzerror_, bzfile_, 0, &nbytes_in, &nbytes_out);

    switch (bzerror_) {
        case BZ_IO_ERROR: throw BagIOException("BZ_IO_ERROR");
    }

    advanceOffset(nbytes_out);
    setCompressedIn(0);
}

void BZ2Stream::startRead() {
    bzfile_ = BZ2_bzReadOpen(&bzerror_, getFilePointer(), verbosity_, 0, getUnused(), getUnusedLength());

    switch (bzerror_) {
        case BZ_OK: break;
        default: {
            BZ2_bzReadClose(&bzerror_, bzfile_);
            throw BagException("Error opening file for reading compressed stream");
        }
    }

    clearUnused();
}

void BZ2Stream::read(void* ptr, size_t size) {
    if (!bzfile_) {
        throw BagException("cannot read from unopened bzfile");
    }

    BZ2_bzRead(&bzerror_, bzfile_, ptr, size);

    advanceOffset(size);

    switch (bzerror_) {
    case BZ_OK: return;
    case BZ_STREAM_END:
        if (getUnused() || getUnusedLength() > 0)
            CONSOLE_BRIDGE_logError("unused data already available");
        else {
            char* unused;
            int nUnused;
            BZ2_bzReadGetUnused(&bzerror_, bzfile_, (void**) &unused, &nUnused);
            setUnused(unused);
            setUnusedLength(nUnused);
        }
        return;
    case BZ_IO_ERROR:         throw BagIOException("BZ_IO_ERROR: error reading from compressed stream");                                break;
    case BZ_UNEXPECTED_EOF:   throw BagIOException("BZ_UNEXPECTED_EOF: compressed stream ended before logical end-of-stream detected"); break;
    case BZ_DATA_ERROR:       throw BagIOException("BZ_DATA_ERROR: data integrity error detected in compressed stream");                break;
    case BZ_DATA_ERROR_MAGIC: throw BagIOException("BZ_DATA_ERROR_MAGIC: stream does not begin with requisite header bytes");           break;
    case BZ_MEM_ERROR:        throw BagIOException("BZ_MEM_ERROR: insufficient memory available");                                      break;
    }
}

void BZ2Stream::stopRead() {
    if (!bzfile_) {
        throw BagException("cannot close unopened bzfile");
    }

    BZ2_bzReadClose(&bzerror_, bzfile_);

    switch (bzerror_) {
        case BZ_IO_ERROR: throw BagIOException("BZ_IO_ERROR");
    }
}

void BZ2Stream::decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len) {
    int result = BZ2_bzBuffToBuffDecompress((char*) dest, &dest_len, (char*) source, source_len, 0, verbosity_);

    switch (result) {
    case BZ_OK:               break;
    case BZ_CONFIG_ERROR:     throw BagException("library has been mis-compiled"); break;
    case BZ_PARAM_ERROR:      throw BagException("dest is NULL or destLen is NULL or small != 0 && small != 1 or verbosity < 0 or verbosity > 4"); break;
    case BZ_MEM_ERROR:        throw BagException("insufficient memory is available"); break;
    case BZ_OUTBUFF_FULL:     throw BagException("size of the compressed data exceeds *destLen"); break;
    case BZ_DATA_ERROR:       throw BagException("data integrity error was detected in the compressed data"); break;
    case BZ_DATA_ERROR_MAGIC: throw BagException("compressed data doesn't begin with the right magic bytes"); break;
    case BZ_UNEXPECTED_EOF:   throw BagException("compressed data ends unexpectedly"); break;
    }
}

} // namespace rosbag