Merge "floss: Generalize mSBC decode buffer" into main (93d44a83) · Commits · e / os / android_packages_modules_Bluetooth

system/stack/btm/btm_sco_hci.cc

+107 −18

Original line number	Diff line number	Diff line
		@@ -396,9 +396,40 @@ struct tBTM_MSBC_INFO {
		size_t packet_size; /* SCO mSBC packet size supported by lower layer */
		size_t buf_size; /* The size of the buffer, determined by the packet_size. */

		enum decode_buf_state {
		DECODE_BUF_EMPTY,
		DECODE_BUF_FULL,

		// Neither empty nor full.
		DECODE_BUF_HALFFULL,
		};

		uint8_t* packet_buf; /* Temporary buffer to store the data */
		uint8_t* msbc_decode_buf; /* Buffer to store mSBC packets to decode */
		size_t decode_buf_wo; /* Write offset of the decode buffer */
		size_t decode_buf_ro; /* Read offset of the decode buffer */

		/* Within the circular buffer, which can be visualized as having
		two halves, mirror indicators track the pointer's location,
		signaling whether it resides in the first or second segment:

		[buf_size-1] ┼ - - -─┼ [0]
		│ │
		│ │
		wo = x, wo_mirror = 0 ^ v ro = x, ro_mirror = 1
		│ │
		│ │
		[0] ┼ - - - ┼ [buf_size-1]
		(First Half) (Second Half)
		*/
		bool decode_buf_wo_mirror; /* The mirror indicator specifies whether
		the write pointer is currently located
		in the first or second half of the
		circular buffer */
		bool decode_buf_ro_mirror; /* The mirror indicator specifies whether
		the read pointer is currently located
		in the first or second half of the
		circular buffer */
		bool read_corrupted; /* If the current mSBC packet read is corrupted */

		uint8_t* msbc_encode_buf; /* Buffer to store the encoded SCO packets */
		@@ -444,6 +475,9 @@ struct tBTM_MSBC_INFO {
		size_t init(size_t pkt_size) {
		decode_buf_wo = 0;
		decode_buf_ro = 0;
		decode_buf_wo_mirror = false;
		decode_buf_ro_mirror = false;

		encode_buf_wo = 0;
		encode_buf_ro = 0;

		@@ -451,6 +485,9 @@ struct tBTM_MSBC_INFO {
		if (pkt_size == packet_size) return packet_size;
		packet_size = pkt_size;

		if (packet_buf) osi_free(packet_buf);
		packet_buf = (uint8_t*)osi_calloc(packet_size);

		if (msbc_decode_buf) osi_free(msbc_decode_buf);
		msbc_decode_buf = (uint8_t*)osi_calloc(buf_size);

		@@ -473,6 +510,7 @@ struct tBTM_MSBC_INFO {

		void deinit() {
		if (msbc_decode_buf) osi_free(msbc_decode_buf);
		if (packet_buf) osi_free(packet_buf);
		if (msbc_encode_buf) osi_free(msbc_encode_buf);
		if (plc) {
		plc->deinit();
		@@ -481,28 +519,66 @@ struct tBTM_MSBC_INFO {
		if (pkt_status) osi_free_and_reset((void**)&pkt_status);
		}

		size_t decodable() { return decode_buf_wo - decode_buf_ro; }
		void incr_buf_offset(size_t& offset, bool& mirror, size_t bsize,
		size_t amount) {
		if (bsize - offset > amount) {
		offset += amount;
		return;
		}

		mirror = !mirror;
		offset = amount - (bsize - offset);
		}

		decode_buf_state decode_buf_status() {
		if (decode_buf_ro == decode_buf_wo) {
		if (decode_buf_ro_mirror == decode_buf_wo_mirror) return DECODE_BUF_EMPTY;
		return DECODE_BUF_FULL;
		}
		return DECODE_BUF_HALFFULL;
		}

		size_t decode_buf_data_len() {
		switch (decode_buf_status()) {
		case DECODE_BUF_EMPTY:
		return 0;
		case DECODE_BUF_FULL:
		return buf_size;
		case DECODE_BUF_HALFFULL:
		default:
		if (decode_buf_wo > decode_buf_ro) return decode_buf_wo - decode_buf_ro;
		return buf_size - (decode_buf_ro - decode_buf_wo);
		};
		}

		size_t decode_buf_avail_len() { return buf_size - decode_buf_data_len(); }

		void mark_pkt_decoded() {
		if (decode_buf_ro + BTM_MSBC_PKT_LEN > decode_buf_wo) {
		if (decode_buf_data_len() < BTM_MSBC_PKT_LEN) {
		LOG_ERROR("Trying to mark read offset beyond write offset.");
		return;
		}

		decode_buf_ro += BTM_MSBC_PKT_LEN;
		if (decode_buf_ro == decode_buf_wo) {
		decode_buf_ro = 0;
		decode_buf_wo = 0;
		}
		incr_buf_offset(decode_buf_ro, decode_buf_ro_mirror, buf_size,
		BTM_MSBC_PKT_LEN);
		}

		size_t write(const std::vector<uint8_t>& input) {
		if (input.size() > buf_size - decode_buf_wo) {
		if (input.size() > decode_buf_avail_len()) {
		return 0;
		}

		if (buf_size - decode_buf_wo > input.size()) {
		std::copy(input.begin(), input.end(), msbc_decode_buf + decode_buf_wo);
		decode_buf_wo += input.size();
		} else {
		std::copy(input.begin(), input.begin() + buf_size - decode_buf_wo,
		msbc_decode_buf + decode_buf_wo);
		std::copy(input.begin() + buf_size - decode_buf_wo, input.end(),
		msbc_decode_buf);
		}

		incr_buf_offset(decode_buf_wo, decode_buf_wo_mirror, buf_size,
		input.size());
		return input.size();
		}

		@@ -513,12 +589,14 @@ struct tBTM_MSBC_INFO {
		}

		size_t rp = 0;
		while (rp < BTM_MSBC_PKT_LEN &&
		decode_buf_wo - (decode_buf_ro + rp) >= BTM_MSBC_PKT_LEN) {
		if ((msbc_decode_buf[decode_buf_ro + rp] != BTM_MSBC_H2_HEADER_0) \|\|
		size_t data_len = decode_buf_data_len();
		while (rp < BTM_MSBC_PKT_LEN && data_len - rp >= BTM_MSBC_PKT_LEN) {
		if ((msbc_decode_buf[(decode_buf_ro + rp) % buf_size] !=
		BTM_MSBC_H2_HEADER_0) \|\|
		(!verify_h2_header_seq_num(
		msbc_decode_buf[decode_buf_ro + rp + 1])) \|\|
		(msbc_decode_buf[decode_buf_ro + rp + 2] != BTM_MSBC_SYNC_WORD)) {
		msbc_decode_buf[(decode_buf_ro + rp + 1) % buf_size])) \|\|
		(msbc_decode_buf[(decode_buf_ro + rp + 2) % buf_size] !=
		BTM_MSBC_SYNC_WORD)) {
		rp++;
		continue;
		}
		@@ -526,11 +604,22 @@ struct tBTM_MSBC_INFO {
		if (rp != 0) {
		LOG_WARN("Skipped %lu bytes of mSBC data ahead of a valid mSBC frame",
		(unsigned long)rp);
		decode_buf_ro += rp;
		incr_buf_offset(decode_buf_ro, decode_buf_ro_mirror, buf_size, rp);
		}

		// Get the frame head.
		if (buf_size - decode_buf_ro >= BTM_MSBC_PKT_LEN) {
		return &msbc_decode_buf[decode_buf_ro];
		}

		std::copy(msbc_decode_buf + decode_buf_ro, msbc_decode_buf + buf_size,
		packet_buf);
		std::copy(msbc_decode_buf,
		msbc_decode_buf + BTM_MSBC_PKT_LEN - (buf_size - decode_buf_ro),
		packet_buf + (buf_size - decode_buf_ro));
		return packet_buf;
		}

		return nullptr;
		}

		@@ -650,7 +739,7 @@ size_t decode(const uint8_t** out_data) {
		return 0;
		}

		if (msbc_info->decodable() < BTM_MSBC_PKT_LEN) {
		if (msbc_info->decode_buf_data_len() < BTM_MSBC_PKT_LEN) {
		return 0;
		}