From 9fbe9a5de30c3326bd7015e91c5ba634df49ee25 Mon Sep 17 00:00:00 2001 From: Petteri Aimonen Date: Thu, 1 Mar 2012 13:46:52 +0200 Subject: Refactoring the field encoder interface. Replaced the confusing pb_enc_* functions with new pb_encode_* functions that have a cleaner interface. Updated documentation. Got rid of the endian_copy stuff in pb_encode.c, instead using C casts to do it automatically. This makes the code safer and also reduces binary size by about 5%. Fixes Issue 6. --- pb_encode.c | 170 +++++++++++++++++++++++++++++++++--------------------------- 1 file changed, 93 insertions(+), 77 deletions(-) (limited to 'pb_encode.c') diff --git a/pb_encode.c b/pb_encode.c index 995eb3d..804c1a6 100644 --- a/pb_encode.c +++ b/pb_encode.c @@ -3,6 +3,7 @@ * 2011 Petteri Aimonen */ +#define NANOPB_INTERNALS #include "pb.h" #include "pb_encode.h" #include @@ -220,6 +221,40 @@ bool checkreturn pb_encode_varint(pb_ostream_t *stream, uint64_t value) return pb_write(stream, buffer, i); } +bool checkreturn pb_encode_svarint(pb_ostream_t *stream, int64_t value) +{ + uint64_t zigzagged; + if (value < 0) + zigzagged = ~(value << 1); + else + zigzagged = value << 1; + + return pb_encode_varint(stream, zigzagged); +} + +bool checkreturn pb_encode_fixed32(pb_ostream_t *stream, const void *value) +{ + #ifdef __BIG_ENDIAN__ + uint8_t *bytes = value; + uint8_t lebytes[4] = {bytes[3], bytes[2], bytes[1], bytes[0]}; + return pb_write(stream, lebytes, 4); + #else + return pb_write(stream, (uint8_t*)value, 4); + #endif +} + +bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value) +{ + #ifdef __BIG_ENDIAN__ + uint8_t *bytes[8] = value; + uint8_t lebytes[8] = {bytes[7], bytes[6], bytes[5], bytes[4], + bytes[3], bytes[2], bytes[1], bytes[0]}; + return pb_write(stream, lebytes, 8); + #else + return pb_write(stream, (uint8_t*)value, 8); + #endif +} + bool checkreturn pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, int field_number) { int tag = wiretype | (field_number << 3); @@ -265,71 +300,85 @@ bool checkreturn pb_encode_string(pb_ostream_t *stream, const uint8_t *buffer, s return pb_write(stream, buffer, size); } -/* Field encoders */ - -/* Copy srcsize bytes from src so that values are casted properly. - * On little endian machine, copy to start of dest - * On big endian machine, copy to end of dest - * destsize must always be larger than srcsize - * - * Note: This is the reverse of the endian_copy in pb_decode.c. - */ -static void endian_copy(void *dest, const void *src, size_t destsize, size_t srcsize) +bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct) { -#ifdef __BIG_ENDIAN__ - memcpy((char*)dest + (destsize - srcsize), src, srcsize); -#else - memcpy(dest, src, srcsize); -#endif + /* First calculate the message size using a non-writing substream. */ + pb_ostream_t substream = {0}; + size_t size; + bool status; + + if (!pb_encode(&substream, fields, src_struct)) + return false; + + size = substream.bytes_written; + + if (!pb_encode_varint(stream, size)) + return false; + + if (stream->callback == NULL) + return pb_write(stream, NULL, size); /* Just sizing */ + + if (stream->bytes_written + size > stream->max_size) + return false; + + /* Use a substream to verify that a callback doesn't write more than + * what it did the first time. */ + substream.callback = stream->callback; + substream.state = stream->state; + substream.max_size = size; + substream.bytes_written = 0; + + status = pb_encode(&substream, fields, src_struct); + + stream->bytes_written += substream.bytes_written; + stream->state = substream.state; + + if (substream.bytes_written != size) + return false; + + return status; } +/* Field encoders */ + bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src) { uint64_t value = 0; - endian_copy(&value, src, sizeof(value), field->data_size); + + switch (field->data_size) + { + case 1: value = *(uint8_t*)src; break; + case 2: value = *(uint16_t*)src; break; + case 4: value = *(uint32_t*)src; break; + case 8: value = *(uint64_t*)src; break; + default: return false; + } + return pb_encode_varint(stream, value); } bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src) { uint64_t value = 0; - uint64_t zigzagged; - uint64_t signbitmask, xormask; - endian_copy(&value, src, sizeof(value), field->data_size); - signbitmask = (uint64_t)0x80 << (field->data_size * 8 - 8); - xormask = ((uint64_t)-1) >> (64 - field->data_size * 8); - if (value & signbitmask) - zigzagged = ((value ^ xormask) << 1) | 1; - else - zigzagged = value << 1; + switch (field->data_size) + { + case 4: value = *(int32_t*)src; break; + case 8: value = *(int64_t*)src; break; + default: return false; + } - return pb_encode_varint(stream, zigzagged); + return pb_encode_svarint(stream, value); } bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src) { - #ifdef __BIG_ENDIAN__ - uint8_t bytes[8] = {0}; - memcpy(bytes, src, 8); - uint8_t lebytes[8] = {bytes[7], bytes[6], bytes[5], bytes[4], - bytes[3], bytes[2], bytes[1], bytes[0]}; - return pb_write(stream, lebytes, 8); - #else - return pb_write(stream, (uint8_t*)src, 8); - #endif + return pb_encode_fixed64(stream, src); } bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src) { - #ifdef __BIG_ENDIAN__ - uint8_t bytes[4] = {0}; - memcpy(bytes, src, 4); - uint8_t lebytes[4] = {bytes[3], bytes[2], bytes[1], bytes[0]}; - return pb_write(stream, lebytes, 4); - #else - return pb_write(stream, (uint8_t*)src, 4); - #endif + return pb_encode_fixed32(stream, src); } bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src) @@ -345,42 +394,9 @@ bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, co bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src) { - pb_ostream_t substream = {0}; - size_t size; - bool status; - if (field->ptr == NULL) return false; - if (!pb_encode(&substream, (pb_field_t*)field->ptr, src)) - return false; - - size = substream.bytes_written; - - if (!pb_encode_varint(stream, size)) - return false; - - if (stream->callback == NULL) - return pb_write(stream, NULL, size); /* Just sizing */ - - if (stream->bytes_written + size > stream->max_size) - return false; - - /* Use a substream to verify that a callback doesn't write more than - * what it did the first time. */ - substream.callback = stream->callback; - substream.state = stream->state; - substream.max_size = size; - substream.bytes_written = 0; - - status = pb_encode(&substream, (pb_field_t*)field->ptr, src); - - stream->bytes_written += substream.bytes_written; - stream->state = substream.state; - - if (substream.bytes_written != size) - return false; - - return status; + return pb_encode_submessage(stream, (pb_field_t*)field->ptr, src); } -- cgit 1.2.3-korg