LiveSession: Add support for block-by-block fetchFile. (822a489e) · Commits · e / os / android_frameworks_av

media/libstagefright/httplive/LiveSession.cpp

+63 −34

Original line number	Diff line number	Diff line
		@@ -512,15 +512,36 @@ sp<PlaylistFetcher> LiveSession::addFetcher(const char *uri) {
		return info.mFetcher;
		}

		/*
		* Illustration of parameters:
		*
		* 0 `range_offset`
		* +------------+-------------------------------------------------------+--+--+
		* \| \| \| next block to fetch \| \| \|
		* \| \| `source` handle => `out` buffer \| \| \| \|
		* \| `url` file \|<--------- buffer size --------->\|<--- `block_size` -->\| \| \|
		* \| \|<----------- `range_length` / buffer capacity ----------->\| \|
		* \|<------------------------------ file_size ------------------------------->\|
		*
		* Special parameter values:
		* - range_length == -1 means entire file
		* - block_size == 0 means entire range
		*
		*/
		status_t LiveSession::fetchFile(
		const char url, sp<ABuffer> out,
		int64_t range_offset, int64_t range_length) {
		*out = NULL;

		sp<DataSource> source;
		int64_t range_offset, int64_t range_length,
		uint32_t block_size, /* download block size */
		sp<DataSource> source / to return and reuse source */) {
		off64_t size;
		sp<DataSource> temp_source;
		if (source == NULL) {
		source = &temp_source;
		}

		if (*source == NULL) {
		if (!strncasecmp(url, "file://", 7)) {
		source = new FileSource(url + 7);
		*source = new FileSource(url + 7);
		} else if (strncasecmp(url, "http://", 7)
		&& strncasecmp(url, "https://", 8)) {
		return ERROR_UNSUPPORTED;
		@@ -534,7 +555,8 @@ status_t LiveSession::fetchFile(
		"bytes=%lld-%s",
		range_offset,
		range_length < 0
		? "" : StringPrintf("%lld", range_offset + range_length - 1).c_str()).c_str()));
		? "" : StringPrintf("%lld",
		range_offset + range_length - 1).c_str()).c_str()));
		}
		status_t err = mHTTPDataSource->connect(url, &headers);

		@@ -542,23 +564,28 @@ status_t LiveSession::fetchFile(
		return err;
		}

		source = mHTTPDataSource;
		*source = mHTTPDataSource;
		}
		}

		off64_t size;
		status_t err = source->getSize(&size);

		if (err != OK) {
		status_t getSizeErr = (*source)->getSize(&size);
		if (getSizeErr != OK) {
		size = 65536;
		}

		sp<ABuffer> buffer = new ABuffer(size);
		sp<ABuffer> buffer = out != NULL ? out : new ABuffer(size);
		if (*out == NULL) {
		buffer->setRange(0, 0);
		}

		// adjust range_length if only reading partial block
		if (block_size > 0 && (range_length == -1 \|\| buffer->size() + block_size < range_length)) {
		range_length = buffer->size() + block_size;
		}
		for (;;) {
		// Only resize when we don't know the size.
		size_t bufferRemaining = buffer->capacity() - buffer->size();

		if (bufferRemaining == 0) {
		if (bufferRemaining == 0 && getSizeErr != OK) {
		bufferRemaining = 32768;

		ALOGV("increasing download buffer to %d bytes",
		@@ -583,7 +610,9 @@ status_t LiveSession::fetchFile(
		}
		}

		ssize_t n = source->readAt(
		// The DataSource is responsible for informing us of error (n < 0) or eof (n == 0)
		// to help us break out of the loop.
		ssize_t n = (*source)->readAt(
		buffer->size(), buffer->data() + buffer->size(),
		maxBytesToRead);

media/libstagefright/httplive/LiveSession.h

+17 −1

Original line number	Diff line number	Diff line
		@@ -145,9 +145,25 @@ private:
		status_t onSeek(const sp<AMessage> &msg);
		void onFinishDisconnect2();

		// If given a non-zero block_size (default 0), it is used to cap the number of
		// bytes read in from the DataSource. If given a non-NULL buffer, new content
		// is read into the end.
		//
		// The DataSource we read from is responsible for signaling error or EOF to help us
		// break out of the read loop. The DataSource can be returned to the caller, so
		// that the caller can reuse it for subsequent fetches (within the initially
		// requested range).
		//
		// For reused HTTP sources, the caller must download a file sequentially without
		// any overlaps or gaps to prevent reconnection.
		status_t fetchFile(
		const char url, sp<ABuffer> out,
		int64_t range_offset = 0, int64_t range_length = -1);
		/* request/open a file starting at range_offset for range_length bytes */
		int64_t range_offset = 0, int64_t range_length = -1,
		/* download block size */
		uint32_t block_size = 0,
		/* reuse DataSource if doing partial fetch */
		sp<DataSource> *source = NULL);

		sp<M3UParser> fetchPlaylist(
		const char url, uint8_t curPlaylistHash, bool *unchanged);