详解protobuf-c之在C语言中如何使用repeated生成数组和字符串（包含配置pb-callback-t）

/* pb_decode.c -- decode a protobuf using minimal resources * * 2011 Petteri Aimonen <jpa@kapsi.fi> */ /* Use the GCC warn_unused_result attribute to check that all return values * are propagated correctly. On other compilers and gcc before 3.4.0 just * ignore the annotation. */ #if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4) #define checkreturn #else #define checkreturn __attribute__((warn_unused_result)) #endif #include "pb.h" #include "pb_decode.h" #include "pb_common.h" /************************************** * Declarations internal to this file * **************************************/ static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count); static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof); static bool checkreturn read_raw_value(pb_istream_t *stream, pb_wire_type_t wire_type, pb_byte_t *buf, size_t *size); static bool checkreturn decode_basic_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field); static bool checkreturn decode_static_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field); static bool checkreturn decode_pointer_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field); static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field); static bool checkreturn decode_field(pb_istream_t *stream, pb_wire_type_t wire_type, pb_field_iter_t *field); static bool checkreturn default_extension_decoder(pb_istream_t *stream, pb_extension_t *extension, uint32_t tag, pb_wire_type_t wire_type); static bool checkreturn decode_extension(pb_istream_t *stream, uint32_t tag, pb_wire_type_t wire_type, pb_extension_t *extension); static bool pb_field_set_to_default(pb_field_iter_t *field); static bool pb_message_set_to_defaults(pb_field_iter_t *iter); static bool checkreturn pb_dec_bool(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_dec_varint(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_dec_bytes(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_dec_string(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_dec_submessage(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_dec_fixed_length_bytes(pb_istream_t *stream, const pb_field_iter_t *field); static bool checkreturn pb_skip_varint(pb_istream_t *stream); static bool checkreturn pb_skip_string(pb_istream_t *stream); #ifdef PB_ENABLE_MALLOC static bool checkreturn allocate_field(pb_istream_t *stream, void *pData, size_t data_size, size_t array_size); static void initialize_pointer_field(void *pItem, pb_field_iter_t *field); static bool checkreturn pb_release_union_field(pb_istream_t *stream, pb_field_iter_t *field); static void pb_release_single_field(pb_field_iter_t *field); #endif #ifdef PB_WITHOUT_64BIT #define pb_int64_t int32_t #define pb_uint64_t uint32_t #else #define pb_int64_t int64_t #define pb_uint64_t uint64_t #endif typedef struct { uint32_t bitfield[(PB_MAX_REQUIRED_FIELDS + 31) / 32]; } pb_fields_seen_t; /******************************* * pb_istream_t implementation * *******************************/ static bool checkreturn buf_read(pb_istream_t *stream, pb_byte_t *buf, size_t count) { const pb_byte_t *source = (const pb_byte_t*)stream->state; stream->state = (pb_byte_t*)stream->state + count; if (buf != NULL) { memcpy(buf, source, count * sizeof(pb_byte_t)); } return true; } bool checkreturn pb_read(pb_istream_t *stream, pb_byte_t *buf, size_t count) { if (count == 0) return true; #ifndef PB_BUFFER_ONLY if (buf == NULL && stream->callback != buf_read) { /* Skip input bytes */ pb_byte_t tmp[16]; while (count > 16) { if (!pb_read(stream, tmp, 16)) return false; count -= 16; } return pb_read(stream, tmp, count); } #endif if (stream->bytes_left < count) PB_RETURN_ERROR(stream, "end-of-stream"); #ifndef PB_BUFFER_ONLY if (!stream->callback(stream, buf, count)) PB_RETURN_ERROR(stream, "io error"); #else if (!buf_read(stream, buf, count)) return false; #endif if (stream->bytes_left < count) stream->bytes_left = 0; else stream->bytes_left -= count; return true; } /* Read a single byte from input stream. buf may not be NULL. * This is an optimization for the varint decoding. */ static bool checkreturn pb_readbyte(pb_istream_t *stream, pb_byte_t *buf) { if (stream->bytes_left == 0) PB_RETURN_ERROR(stream, "end-of-stream"); #ifndef PB_BUFFER_ONLY if (!stream->callback(stream, buf, 1)) PB_RETURN_ERROR(stream, "io error"); #else *buf = *(const pb_byte_t*)stream->state; stream->state = (pb_byte_t*)stream->state + 1; #endif stream->bytes_left--; return true; } pb_istream_t pb_istream_from_buffer(const pb_byte_t *buf, size_t msglen) { pb_istream_t stream; /* Cast away the const from buf without a compiler error. We are * careful to use it only in a const manner in the callbacks. */ union { void *state; const void *c_state; } state; #ifdef PB_BUFFER_ONLY stream.callback = NULL; #else stream.callback = &buf_read; #endif state.c_state = buf; stream.state = state.state; stream.bytes_left = msglen; #ifndef PB_NO_ERRMSG stream.errmsg = NULL; #endif return stream; } /******************** * Helper functions * ********************/ static bool checkreturn pb_decode_varint32_eof(pb_istream_t *stream, uint32_t *dest, bool *eof) { pb_byte_t byte; uint32_t result; if (!pb_readbyte(stream, &byte)) { if (stream->bytes_left == 0) { if (eof) { *eof = true; } } return false; } if ((byte & 0x80) == 0) { /* Quick case, 1 byte value */ result = byte; } else { /* Multibyte case */ uint_fast8_t bitpos = 7; result = byte & 0x7F; do { if (!pb_readbyte(stream, &byte)) return false; if (bitpos >= 32) { /* Note: The varint could have trailing 0x80 bytes, or 0xFF for negative. */ pb_byte_t sign_extension = (bitpos < 63) ? 0xFF : 0x01; bool valid_extension = ((byte & 0x7F) == 0x00 || ((result >> 31) != 0 && byte == sign_extension)); if (bitpos >= 64 || !valid_extension) { PB_RETURN_ERROR(stream, "varint overflow"); } } else if (bitpos == 28) { if ((byte & 0x70) != 0 && (byte & 0x78) != 0x78) { PB_RETURN_ERROR(stream, "varint overflow"); } result |= (uint32_t)(byte & 0x0F) << bitpos; } else { result |= (uint32_t)(byte & 0x7F) << bitpos; } bitpos = (uint_fast8_t)(bitpos + 7); } while (byte & 0x80); } *dest = result; return true; } bool checkreturn pb_decode_varint32(pb_istream_t *stream, uint32_t *dest) { return pb_decode_varint32_eof(stream, dest, NULL); } #ifndef PB_WITHOUT_64BIT bool checkreturn pb_decode_varint(pb_istream_t *stream, uint64_t *dest) { pb_byte_t byte; uint_fast8_t bitpos = 0; uint64_t result = 0; do { if (!pb_readbyte(str