A small memory footprint AMQP implimentation
Dependents: iothub_client_sample_amqp remote_monitoring simplesample_amqp
amqp_frame_codec.c
- Committer:
- AzureIoTClient
- Date:
- 2017-06-30
- Revision:
- 28:add19eb7defa
- Parent:
- 27:d74f1cea23e1
- Child:
- 30:0407b2db334c
File content as of revision 28:add19eb7defa:
// Copyright (c) Microsoft. All rights reserved. // Licensed under the MIT license. See LICENSE file in the project root for full license information. #include <stdlib.h> #include <stdint.h> #include <stddef.h> #include <string.h> #include "azure_c_shared_utility/optimize_size.h" #include "azure_c_shared_utility/gballoc.h" #include "azure_c_shared_utility/xlogging.h" #include "azure_uamqp_c/amqp_frame_codec.h" #include "azure_uamqp_c/frame_codec.h" #include "azure_uamqp_c/amqpvalue.h" typedef enum AMQP_FRAME_DECODE_STATE_TAG { AMQP_FRAME_DECODE_FRAME, AMQP_FRAME_DECODE_ERROR } AMQP_FRAME_DECODE_STATE; typedef struct AMQP_FRAME_CODEC_INSTANCE_TAG { FRAME_CODEC_HANDLE frame_codec; /* decode */ AMQP_FRAME_RECEIVED_CALLBACK frame_received_callback; AMQP_EMPTY_FRAME_RECEIVED_CALLBACK empty_frame_received_callback; AMQP_FRAME_CODEC_ERROR_CALLBACK error_callback; void* callback_context; AMQPVALUE_DECODER_HANDLE decoder; AMQP_FRAME_DECODE_STATE decode_state; AMQP_VALUE decoded_performative; } AMQP_FRAME_CODEC_INSTANCE; static void amqp_value_decoded(void* context, AMQP_VALUE decoded_value) { AMQP_FRAME_CODEC_INSTANCE* amqp_frame_codec_instance = (AMQP_FRAME_CODEC_INSTANCE*)context; uint64_t performative_descriptor_ulong; AMQP_VALUE descriptor = amqpvalue_get_inplace_descriptor(decoded_value); /* Codes_SRS_AMQP_FRAME_CODEC_01_060: [If any error occurs while decoding a frame, the decoder shall switch to an error state where decoding shall not be possible anymore.] */ if ((descriptor == NULL) || (amqpvalue_get_ulong(descriptor, &performative_descriptor_ulong) != 0) || /* Codes_SRS_AMQP_FRAME_CODEC_01_003: [The performative MUST be one of those defined in section 2.7 and is encoded as a described type in the AMQP type system.] */ (performative_descriptor_ulong < AMQP_OPEN) || (performative_descriptor_ulong > AMQP_CLOSE)) { /* Codes_SRS_AMQP_FRAME_CODEC_01_060: [If any error occurs while decoding a frame, the decoder shall switch to an error state where decoding shall not be possible anymore.] */ amqp_frame_codec_instance->decode_state = AMQP_FRAME_DECODE_ERROR; } else { amqp_frame_codec_instance->decoded_performative = decoded_value; } } static void frame_received(void* context, const unsigned char* type_specific, uint32_t type_specific_size, const unsigned char* frame_body, uint32_t frame_body_size) { AMQP_FRAME_CODEC_INSTANCE* amqp_frame_codec_instance = (AMQP_FRAME_CODEC_INSTANCE*)context; uint16_t channel; switch (amqp_frame_codec_instance->decode_state) { default: /* Codes_SRS_AMQP_FRAME_CODEC_01_050: [All subsequent decoding shall fail and no AMQP frames shall be indicated from that point on to the consumers of amqp_frame_codec.] */ case AMQP_FRAME_DECODE_ERROR: break; case AMQP_FRAME_DECODE_FRAME: /* Codes_SRS_AMQP_FRAME_CODEC_01_049: [If not enough type specific bytes are received to decode the channel number, the decoding shall stop with an error.] */ if (type_specific_size < 2) { amqp_frame_codec_instance->decode_state = AMQP_FRAME_DECODE_ERROR; /* Codes_SRS_AMQP_FRAME_CODEC_01_069: [If any error occurs while decoding a frame, the decoder shall indicate the error by calling the amqp_frame_codec_error_callback and passing to it the callback context argument that was given in amqp_frame_codec_create.] */ amqp_frame_codec_instance->error_callback(amqp_frame_codec_instance->callback_context); } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_001: [Bytes 6 and 7 of an AMQP frame contain the channel number ] */ channel = ((uint16_t)type_specific[0]) << 8; channel += type_specific[1]; if (frame_body_size == 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_048: [When a frame header is received from frame_codec and the frame payload size is 0, empty_frame_received_callback shall be invoked, while passing the channel number as argument.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_007: [An AMQP frame with no body MAY be used to generate artificial traffic as needed to satisfy any negotiated idle timeout interval ] */ amqp_frame_codec_instance->empty_frame_received_callback(amqp_frame_codec_instance->callback_context, channel); } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_051: [If the frame payload is greater than 0, amqp_frame_codec shall decode the performative as a described AMQP type.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_002: [The frame body is defined as a performative followed by an opaque payload.] */ amqp_frame_codec_instance->decoded_performative = NULL; while ((frame_body_size > 0) && (amqp_frame_codec_instance->decoded_performative == NULL) && (amqp_frame_codec_instance->decode_state != AMQP_FRAME_DECODE_ERROR)) { /* Codes_SRS_AMQP_FRAME_CODEC_01_052: [Decoding the performative shall be done by feeding the bytes to the decoder create in amqp_frame_codec_create.] */ if (amqpvalue_decode_bytes(amqp_frame_codec_instance->decoder, frame_body, 1) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_060: [If any error occurs while decoding a frame, the decoder shall switch to an error state where decoding shall not be possible anymore.] */ amqp_frame_codec_instance->decode_state = AMQP_FRAME_DECODE_ERROR; } else { frame_body_size--; frame_body++; } } if (amqp_frame_codec_instance->decode_state == AMQP_FRAME_DECODE_ERROR) { /* Codes_SRS_AMQP_FRAME_CODEC_01_069: [If any error occurs while decoding a frame, the decoder shall indicate the error by calling the amqp_frame_codec_error_callback and passing to it the callback context argument that was given in amqp_frame_codec_create.] */ amqp_frame_codec_instance->error_callback(amqp_frame_codec_instance->callback_context); } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_004: [The remaining bytes in the frame body form the payload for that frame.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_067: [When the performative is decoded, the rest of the frame_bytes shall not be given to the AMQP decoder, but they shall be buffered so that later they are given to the frame_received callback.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_054: [Once the performative is decoded and all frame payload bytes are received, the callback frame_received_callback shall be called.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_068: [A pointer to all the payload bytes shall also be passed to frame_received_callback.] */ amqp_frame_codec_instance->frame_received_callback(amqp_frame_codec_instance->callback_context, channel, amqp_frame_codec_instance->decoded_performative, frame_body, frame_body_size); } } } break; } } static int encode_bytes(void* context, const unsigned char* bytes, size_t length) { PAYLOAD* payload = (PAYLOAD*)context; (void)memcpy((unsigned char*)payload->bytes + payload->length, bytes, length); payload->length += length; return 0; } /* Codes_SRS_AMQP_FRAME_CODEC_01_011: [amqp_frame_codec_create shall create an instance of an amqp_frame_codec and return a non-NULL handle to it.] */ AMQP_FRAME_CODEC_HANDLE amqp_frame_codec_create(FRAME_CODEC_HANDLE frame_codec, AMQP_FRAME_RECEIVED_CALLBACK frame_received_callback, AMQP_EMPTY_FRAME_RECEIVED_CALLBACK empty_frame_received_callback, AMQP_FRAME_CODEC_ERROR_CALLBACK amqp_frame_codec_error_callback, void* callback_context) { AMQP_FRAME_CODEC_INSTANCE* result; /* Codes_SRS_AMQP_FRAME_CODEC_01_012: [If any of the arguments frame_codec, frame_received_callback, amqp_frame_codec_error_callback or empty_frame_received_callback is NULL, amqp_frame_codec_create shall return NULL.] */ if ((frame_codec == NULL) || (frame_received_callback == NULL) || (empty_frame_received_callback == NULL) || (amqp_frame_codec_error_callback == NULL)) { LogError("Bad arguments: frame_codec = %p, frame_received_callback = %p, empty_frame_received_callback = %p, amqp_frame_codec_error_callback = %p", frame_codec, frame_received_callback, empty_frame_received_callback, amqp_frame_codec_error_callback); result = NULL; } else { result = (AMQP_FRAME_CODEC_INSTANCE*)malloc(sizeof(AMQP_FRAME_CODEC_INSTANCE)); /* Codes_SRS_AMQP_FRAME_CODEC_01_020: [If allocating memory for the new amqp_frame_codec fails, then amqp_frame_codec_create shall fail and return NULL.] */ if (result == NULL) { LogError("Could not allocate memory for AMQP frame codec"); } else { result->frame_codec = frame_codec; result->frame_received_callback = frame_received_callback; result->empty_frame_received_callback = empty_frame_received_callback; result->error_callback = amqp_frame_codec_error_callback; result->callback_context = callback_context; result->decode_state = AMQP_FRAME_DECODE_FRAME; /* Codes_SRS_AMQP_FRAME_CODEC_01_018: [amqp_frame_codec_create shall create a decoder to be used for decoding AMQP values.] */ result->decoder = amqpvalue_decoder_create(amqp_value_decoded, result); if (result->decoder == NULL) { /* Codes_SRS_AMQP_FRAME_CODEC_01_019: [If creating the decoder fails, amqp_frame_codec_create shall fail and return NULL.] */ LogError("Could not create AMQP decoder"); free(result); result = NULL; } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_013: [amqp_frame_codec_create shall subscribe for AMQP frames with the given frame_codec.] */ if (frame_codec_subscribe(frame_codec, FRAME_TYPE_AMQP, frame_received, result) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_014: [If subscribing for AMQP frames fails, amqp_frame_codec_create shall fail and return NULL.] */ LogError("Could not subscribe for received AMQP frames"); amqpvalue_decoder_destroy(result->decoder); free(result); result = NULL; } } } } return result; } void amqp_frame_codec_destroy(AMQP_FRAME_CODEC_HANDLE amqp_frame_codec) { if (amqp_frame_codec == NULL) { /* Codes_SRS_AMQP_FRAME_CODEC_01_016: [If amqp_frame_codec is NULL, amqp_frame_codec_destroy shall do nothing.] */ LogError("NULL amqp_frame_codec"); } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_017: [amqp_frame_codec_destroy shall unsubscribe from receiving AMQP frames from the frame_codec that was passed to amqp_frame_codec_create.] */ (void)frame_codec_unsubscribe(amqp_frame_codec->frame_codec, FRAME_TYPE_AMQP); /* Codes_SRS_AMQP_FRAME_CODEC_01_021: [The decoder created in amqp_frame_codec_create shall be destroyed by amqp_frame_codec_destroy.] */ amqpvalue_decoder_destroy(amqp_frame_codec->decoder); /* Codes_SRS_AMQP_FRAME_CODEC_01_015: [amqp_frame_codec_destroy shall free all resources associated with the amqp_frame_codec instance.] */ free(amqp_frame_codec); } } int amqp_frame_codec_encode_frame(AMQP_FRAME_CODEC_HANDLE amqp_frame_codec, uint16_t channel, const AMQP_VALUE performative, const PAYLOAD* payloads, size_t payload_count, ON_BYTES_ENCODED on_bytes_encoded, void* callback_context) { int result; /* Codes_SRS_AMQP_FRAME_CODEC_01_024: [If frame_codec, performative or on_bytes_encoded is NULL, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ if ((amqp_frame_codec == NULL) || (performative == NULL) || (on_bytes_encoded == NULL)) { LogError("Bad arguments: amqp_frame_codec = %p, performative = %p, on_bytes_encoded = %p", amqp_frame_codec, performative, on_bytes_encoded); result = __FAILURE__; } else { AMQP_VALUE descriptor; uint64_t performative_ulong; size_t encoded_size; if ((descriptor = amqpvalue_get_inplace_descriptor(performative)) == NULL) { /* Codes_SRS_AMQP_FRAME_CODEC_01_029: [If any error occurs during encoding, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ LogError("Getting the descriptor failed"); result = __FAILURE__; } else if (amqpvalue_get_ulong(descriptor, &performative_ulong) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_029: [If any error occurs during encoding, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ LogError("Getting the descriptor ulong failed"); result = __FAILURE__; } /* Codes_SRS_AMQP_FRAME_CODEC_01_008: [The performative MUST be one of those defined in section 2.7 and is encoded as a described type in the AMQP type system.] */ else if ((performative_ulong < AMQP_OPEN) || (performative_ulong > AMQP_CLOSE)) { /* Codes_SRS_AMQP_FRAME_CODEC_01_029: [If any error occurs during encoding, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ LogError("Bad arguments: amqp_frame_codec = %p, performative = %p, on_bytes_encoded = %p", amqp_frame_codec, performative, on_bytes_encoded); result = __FAILURE__; } /* Codes_SRS_AMQP_FRAME_CODEC_01_027: [The encoded size of the performative and its fields shall be obtained by calling amqpvalue_get_encoded_size.] */ else if (amqpvalue_get_encoded_size(performative, &encoded_size) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_029: [If any error occurs during encoding, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ LogError("Getting the encoded size failed"); result = __FAILURE__; } else { unsigned char* amqp_performative_bytes = (unsigned char*)malloc(encoded_size); if (amqp_performative_bytes == NULL) { LogError("Could not allocate performative bytes"); result = __FAILURE__; } else { PAYLOAD* new_payloads = (PAYLOAD*)malloc(sizeof(PAYLOAD) * (payload_count + 1)); if (new_payloads == NULL) { LogError("Could not allocate frame payloads"); result = __FAILURE__; } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_070: [The payloads argument for frame_codec_encode_frame shall be made of the payload for the encoded performative and the payloads passed to amqp_frame_codec_encode_frame.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_028: [The encode result for the performative shall be placed in a PAYLOAD structure.] */ new_payloads[0].bytes = amqp_performative_bytes; new_payloads[0].length = 0; if (payload_count > 0) { (void)memcpy(new_payloads + 1, payloads, sizeof(PAYLOAD) * payload_count); } if (amqpvalue_encode(performative, encode_bytes, &new_payloads[0]) != 0) { LogError("amqpvalue_encode failed"); result = __FAILURE__; } else { unsigned char channel_bytes[2]; channel_bytes[0] = channel >> 8; channel_bytes[1] = channel & 0xFF; /* Codes_SRS_AMQP_FRAME_CODEC_01_005: [Bytes 6 and 7 of an AMQP frame contain the channel number ] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_025: [amqp_frame_codec_encode_frame shall encode the frame header by using frame_codec_encode_frame.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_006: [The frame body is defined as a performative followed by an opaque payload.] */ if (frame_codec_encode_frame(amqp_frame_codec->frame_codec, FRAME_TYPE_AMQP, new_payloads, payload_count + 1, channel_bytes, sizeof(channel_bytes), on_bytes_encoded, callback_context) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_029: [If any error occurs during encoding, amqp_frame_codec_encode_frame shall fail and return a non-zero value.] */ LogError("frame_codec_encode_frame failed"); result = __FAILURE__; } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_022: [amqp_frame_codec_begin_encode_frame shall encode the frame header and AMQP performative in an AMQP frame and on success it shall return 0.] */ result = 0; } } free(new_payloads); } free(amqp_performative_bytes); } } } return result; } /* Codes_SRS_AMQP_FRAME_CODEC_01_042: [amqp_frame_codec_encode_empty_frame shall encode a frame with no payload.] */ /* Codes_SRS_AMQP_FRAME_CODEC_01_010: [An AMQP frame with no body MAY be used to generate artificial traffic as needed to satisfy any negotiated idle timeout interval ] */ int amqp_frame_codec_encode_empty_frame(AMQP_FRAME_CODEC_HANDLE amqp_frame_codec, uint16_t channel, ON_BYTES_ENCODED on_bytes_encoded, void* callback_context) { int result; /* Codes_SRS_AMQP_FRAME_CODEC_01_045: [If amqp_frame_codec is NULL, amqp_frame_codec_encode_empty_frame shall fail and return a non-zero value.] */ if (amqp_frame_codec == NULL) { LogError("NULL amqp_frame_codec"); result = __FAILURE__; } else { unsigned char channel_bytes[2]; channel_bytes[0] = channel >> 8; channel_bytes[1] = channel & 0xFF; /* Codes_SRS_AMQP_FRAME_CODEC_01_044: [amqp_frame_codec_encode_empty_frame shall use frame_codec_encode_frame to encode the frame.] */ if (frame_codec_encode_frame(amqp_frame_codec->frame_codec, FRAME_TYPE_AMQP, NULL, 0, channel_bytes, sizeof(channel_bytes), on_bytes_encoded, callback_context) != 0) { /* Codes_SRS_AMQP_FRAME_CODEC_01_046: [If encoding fails in any way, amqp_frame_codec_encode_empty_frame shall fail and return a non-zero value.] */ LogError("frame_codec_encode_frame failed when encoding empty frame"); result = __FAILURE__; } else { /* Codes_SRS_AMQP_FRAME_CODEC_01_043: [On success, amqp_frame_codec_encode_empty_frame shall return 0.] */ result = 0; } } return result; }