void mpack_reader_init_error(mpack_reader_t* reader, mpack_error_t error) {
mpack_memset(reader, 0, sizeof(*reader));
reader->error = error;
mpack_log("===========================\n");
mpack_log("initializing reader error state %i\n", (int)error);
}
void mpack_reader_init(mpack_reader_t* reader, char* buffer, size_t size, size_t count) {
mpack_assert(buffer != NULL, "buffer is NULL");
mpack_memset(reader, 0, sizeof(*reader));
reader->buffer = buffer;
reader->size = size;
reader->left = count;
#if MPACK_READ_TRACKING
mpack_reader_flag_if_error(reader, mpack_track_init(&reader->track));
#endif
mpack_log("===========================\n");
mpack_log("initializing reader with buffer size %i\n", (int)size);
}
mpack_tag_t mpack_peek_tag(mpack_reader_t* reader) {
mpack_log("peeking tag\n");
// make sure we can peek a tag
if (mpack_reader_error(reader) != mpack_ok)
return mpack_tag_nil();
if (mpack_reader_track_peek_element(reader) != mpack_ok)
return mpack_tag_nil();
mpack_tag_t tag;
mpack_memset(&tag, 0, sizeof(tag));
if (mpack_parse_tag(reader, &tag) == 0)
return mpack_tag_nil();
return tag;
}
static void mpack_writer_clear(mpack_writer_t* writer) {
writer->flush = NULL;
writer->error_fn = NULL;
writer->teardown = NULL;
writer->context = NULL;
writer->buffer = NULL;
writer->size = 0;
writer->used = 0;
writer->error = mpack_ok;
#if MPACK_WRITE_TRACKING
mpack_memset(&writer->track, 0, sizeof(writer->track));
#endif
}
mpack_tag_t mpack_read_tag(mpack_reader_t* reader) {
mpack_log("reading tag\n");
// make sure we can read a tag
if (mpack_reader_error(reader) != mpack_ok)
return mpack_tag_nil();
if (mpack_reader_track_element(reader) != mpack_ok)
return mpack_tag_nil();
mpack_tag_t tag;
mpack_memset(&tag, 0, sizeof(tag));
size_t count = mpack_parse_tag(reader, &tag);
if (count == 0)
return mpack_tag_nil();
#if MPACK_READ_TRACKING
mpack_error_t track_error = mpack_ok;
switch (tag.type) {
case mpack_type_map:
case mpack_type_array:
track_error = mpack_track_push(&reader->track, tag.type, tag.v.l);
break;
case mpack_type_str:
case mpack_type_bin:
case mpack_type_ext:
track_error = mpack_track_push(&reader->track, tag.type, tag.v.n);
break;
default:
break;
}
if (track_error != mpack_ok) {
mpack_reader_flag_error(reader, track_error);
return mpack_tag_nil();
}
#endif
// the tag is guaranteed to have been read out of
// the buffer, so we advance past it
reader->pos += count;
reader->left -= count;
return tag;
}
void mpack_reader_init_data(mpack_reader_t* reader, const char* data, size_t count) {
mpack_assert(data != NULL, "data is NULL");
mpack_memset(reader, 0, sizeof(*reader));
reader->left = count;
// unfortunately we have to cast away the const to store the buffer,
// but we won't be modifying it because there's no fill function.
// the buffer size is left at 0 to ensure no fill function can be
// set or used (see mpack_reader_set_fill().)
#ifdef __cplusplus
reader->buffer = const_cast<char*>(data);
#else
reader->buffer = (char*)data;
#endif
#if MPACK_READ_TRACKING
mpack_reader_flag_if_error(reader, mpack_track_init(&reader->track));
#endif
mpack_log("===========================\n");
mpack_log("initializing reader with data size %i\n", (int)count);
}
// Reads count bytes into p. Used when there are not enough bytes
// left in the buffer to satisfy a read.
void mpack_read_native_big(mpack_reader_t* reader, char* p, size_t count) {
mpack_assert(count == 0 || p != NULL, "data pointer for %i bytes is NULL", (int)count);
if (mpack_reader_error(reader) != mpack_ok) {
mpack_memset(p, 0, count);
return;
}
mpack_log("big read for %i bytes into %p, %i left in buffer, buffer size %i\n",
(int)count, p, (int)reader->left, (int)reader->size);
if (count <= reader->left) {
mpack_assert(0,
"big read requested for %i bytes, but there are %i bytes "
"left in buffer. call mpack_read_native() instead",
(int)count, (int)reader->left);
mpack_reader_flag_error(reader, mpack_error_bug);
mpack_memset(p, 0, count);
return;
}
// we'll need a fill function to get more data. if there's no
// fill function, the buffer should contain an entire MessagePack
// object, so we raise mpack_error_invalid instead of mpack_error_io
// on truncated data.
if (reader->fill == NULL) {
mpack_reader_flag_error(reader, mpack_error_invalid);
mpack_memset(p, 0, count);
return;
}
if (reader->size == 0) {
// somewhat debatable what error should be returned here. when
// initializing a reader with an in-memory buffer it's not
// necessarily a bug if the data is blank; it might just have
// been truncated to zero. for this reason we return the same
// error as if the data was truncated.
mpack_reader_flag_error(reader, mpack_error_io);
mpack_memset(p, 0, count);
return;
}
// flush what's left of the buffer
if (reader->left > 0) {
mpack_log("flushing %i bytes remaining in buffer\n", (int)reader->left);
mpack_memcpy(p, reader->buffer + reader->pos, reader->left);
count -= reader->left;
p += reader->left;
reader->pos += reader->left;
reader->left = 0;
}
// we read only in multiples of the buffer size. read the middle portion, if any
size_t middle = count - (count % reader->size);
if (middle > 0) {
mpack_log("reading %i bytes in middle\n", (int)middle);
if (mpack_fill(reader, p, middle) < middle) {
mpack_reader_flag_error(reader, mpack_error_io);
mpack_memset(p, 0, count);
return;
}
count -= middle;
p += middle;
if (count == 0)
return;
}
// fill the buffer
reader->pos = 0;
reader->left = mpack_fill(reader, reader->buffer, reader->size);
mpack_log("filled %i bytes into buffer\n", (int)reader->left);
if (reader->left < count) {
mpack_reader_flag_error(reader, mpack_error_io);
mpack_memset(p, 0, count);
return;
}
// serve the remainder
mpack_log("serving %i remaining bytes from %p to %p\n", (int)count, reader->buffer+reader->pos,p);
mpack_memcpy(p, reader->buffer + reader->pos, count);
reader->pos += count;
reader->left -= count;
}
