uint64_t S3KeyReader::read(char* buf, uint64_t count) {
uint64_t fileLen = this->offsetMgr.getKeySize();
uint64_t readLen = 0;
do {
// confirm there is no more available data, done with this file
if (this->transferredKeyLen >= fileLen) {
return 0;
}
ChunkBuffer& buffer = chunkBuffers[this->curReadingChunk % this->numOfChunks];
readLen = buffer.read(buf, count);
CHECK_OR_DIE_MSG(!this->sharedError, "%s", this->sharedErrorMessage.c_str());
this->transferredKeyLen += readLen;
if (readLen < count) {
this->curReadingChunk++;
CHECK_OR_DIE_MSG(!buffer.isError(), "%s", "Error occurs while downloading, skip");
}
// retry to confirm whether thread reading is finished or chunk size is
// divisible by get()'s buffer size
} while (readLen == 0);
return readLen;
}
void S3KeyReader::open(const ReaderParams& params) {
this->sharedError = false;
this->sharedErrorMessage.clear();
this->numOfChunks = params.getNumOfChunks();
CHECK_OR_DIE_MSG(this->numOfChunks > 0, "%s", "numOfChunks must not be zero");
this->region = params.getRegion();
this->credential = params.getCred();
this->offsetMgr.setKeySize(params.getKeySize());
this->offsetMgr.setChunkSize(params.getChunkSize());
CHECK_OR_DIE_MSG(params.getChunkSize() > 0, "%s", "chunk size must be greater than zero");
for (uint64_t i = 0; i < this->numOfChunks; i++) {
// when vector reallocate memory, it will copy object.
// chunkData must be initialized after all copy.
this->chunkBuffers.push_back(ChunkBuffer(params.getKeyUrl(), *this));
}
for (uint64_t i = 0; i < this->numOfChunks; i++) {
this->chunkBuffers[i].init();
this->chunkBuffers[i].setS3interface(this->s3interface);
pthread_t thread;
pthread_create(&thread, NULL, DownloadThreadFunc, &this->chunkBuffers[i]);
this->threads.push_back(thread);
}
return;
}
// Copy constructor will copy members, but chunkData must not be initialized before copy.
// otherwise when worked with vector it will be freed twice.
void ChunkBuffer::init() {
CHECK_OR_DIE_MSG(chunkData == NULL, "%s", "Error: reinitializing chunkBuffer.");
chunkData = new char[offsetMgr.getChunkSize()];
CHECK_OR_DIE_MSG(chunkData != NULL, "%s", "Failed to allocate Buffer, no enough memory?");
pthread_mutex_init(&this->statusMutex, NULL);
pthread_cond_init(&this->statusCondVar, NULL);
}
uint64_t CompressWriter::write(const char* buf, uint64_t count) {
if (buf == NULL || count == 0) {
return 0;
}
// we assume data block from upper layer is always smaller than gzip chunkbuffer
CHECK_OR_DIE_MSG(count < S3_ZIP_COMPRESS_CHUNKSIZE,
"Data size " PRIu64 " is larger than S3_ZIP_COMPRESS_CHUNKSIZE", count);
this->zstream.next_in = (Byte*)buf;
this->zstream.avail_in = count;
int status = deflate(&this->zstream, Z_NO_FLUSH);
if (status < 0 && status != Z_BUF_ERROR) {
deflateEnd(&this->zstream);
CHECK_OR_DIE_MSG(false, "Failed to compress data: %d, %s", status, this->zstream.msg);
}
this->flush();
return count;
}
void InitRemoteLog() {
if (loginited) {
return;
}
s3ext_logsock_udp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
CHECK_OR_DIE_MSG(s3ext_logsock_udp != -1, "Failed to create socket: %s", strerror(errno));
memset(&s3ext_logserveraddr, 0, sizeof(struct sockaddr_in));
s3ext_logserveraddr.sin_family = AF_INET;
s3ext_logserveraddr.sin_port = htons(s3ext_logserverport);
inet_aton(s3ext_logserverhost.c_str(), &s3ext_logserveraddr.sin_addr);
loginited = true;
}
// ret < len means EMPTY
// that's why it checks if leftLen is larger than *or equal to* len below[1], provides a chance ret
// is 0, which is smaller than len. Otherwise, other functions won't know when to read next buffer.
uint64_t ChunkBuffer::read(char* buf, uint64_t len) {
// QueryCancelPending stops s3_import(), this check is not needed if
// s3_import() every time calls ChunkBuffer->Read() only once, otherwise(as we did in
// downstreamReader->read() for decompression feature before), first call sets buffer to
// ReadyToFill, second call hangs.
CHECK_OR_DIE_MSG(!QueryCancelPending, "%s", "ChunkBuffer reading is interrupted by GPDB");
pthread_mutex_lock(&this->statusMutex);
while (this->status != ReadyToRead) {
pthread_cond_wait(&this->statusCondVar, &this->statusMutex);
}
// Error is shared between all chunks.
if (this->isError()) {
pthread_mutex_unlock(&this->statusMutex);
// Don't throw here. Other chunks will set the shared error message,
// it will be handled by S3KeyReader.
return 0;
}
uint64_t leftLen = this->chunkDataSize - this->curChunkOffset;
uint64_t lenToRead = std::min(len, leftLen);
if (lenToRead != 0) {
memcpy(buf, this->chunkData + this->curChunkOffset, lenToRead);
}
if (len <= leftLen) { // [1]
this->curChunkOffset += lenToRead; // not empty
} else { // empty, reset everything
this->curChunkOffset = 0;
if (!this->isEOF()) {
this->status = ReadyToFill;
Range range = this->offsetMgr.getNextOffset();
this->curFileOffset = range.offset;
this->chunkDataSize = range.length;
pthread_cond_signal(&this->statusCondVar);
}
}
pthread_mutex_unlock(&this->statusMutex);
return lenToRead;
}
void S3CommonReader::open(const ReaderParams ¶ms) {
this->keyReader.setS3interface(s3service);
S3CompressionType compressionType =
s3service->checkCompressionType(params.getKeyUrl(), params.getRegion(), params.getCred());
switch (compressionType) {
case S3_COMPRESSION_GZIP:
this->upstreamReader = &this->decompressReader;
this->decompressReader.setReader(&this->keyReader);
break;
case S3_COMPRESSION_PLAIN:
this->upstreamReader = &this->keyReader;
break;
default:
CHECK_OR_DIE_MSG(false, "%s", "unknown file type");
};
this->upstreamReader->open(params);
}
void CompressWriter::open(const WriterParams& params) {
this->zstream.zalloc = Z_NULL;
this->zstream.zfree = Z_NULL;
this->zstream.opaque = Z_NULL;
// With S3_DEFLATE_WINDOWSBITS, it generates gzip stream with header and trailer
int ret = deflateInit2(&this->zstream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
S3_DEFLATE_WINDOWSBITS, 8, Z_DEFAULT_STRATEGY);
// init them here to get ready for both writer() and close()
this->zstream.next_in = NULL;
this->zstream.avail_in = 0;
this->zstream.next_out = (Byte*)this->out;
this->zstream.avail_out = S3_ZIP_COMPRESS_CHUNKSIZE;
CHECK_OR_DIE_MSG(ret == Z_OK, "Failed to initialize zlib library: %s", this->zstream.msg);
this->writer->open(params);
this->isClosed = false;
}
void CompressWriter::close() {
if (this->isClosed) {
return;
}
int status;
do {
status = deflate(&this->zstream, Z_FINISH);
this->flush();
} while (status == Z_OK);
deflateEnd(&this->zstream);
if (status != Z_STREAM_END) {
CHECK_OR_DIE_MSG(false, "Failed to finish data compression: %d, %s", status,
this->zstream.msg);
}
S3DEBUG("Compression finished: Z_STREAM_END.");
this->writer->close();
this->isClosed = true;
}
