-#ifndef _PB_DECODE_H_
-#define _PB_DECODE_H_
-
/* pb_decode.h: Functions to decode protocol buffers. Depends on pb_decode.c.
- * The main function is pb_decode. You will also need to create an input
- * stream, which is easiest to do with pb_istream_from_buffer().
- *
- * You also need structures and their corresponding pb_field_t descriptions.
- * These are usually generated from .proto-files with a script.
+ * The main function is pb_decode. You also need an input stream, and the
+ * field descriptions created by nanopb_generator.py.
*/
-#include <stdbool.h>
+#ifndef PB_DECODE_H_INCLUDED
+#define PB_DECODE_H_INCLUDED
+
#include "pb.h"
-/* Lightweight input stream.
- * You can provide a callback function for reading or use
- * pb_istream_from_buffer.
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Structure for defining custom input streams. You will need to provide
+ * a callback function to read the bytes from your storage, which can be
+ * for example a file or a network socket.
*
- * Rules for callback:
+ * The callback must conform to these rules:
+ *
* 1) Return false on IO errors. This will cause decoding to abort.
- *
- * 2) If buf is NULL, read but don't store bytes ("skip input").
- *
- * 3) You can use state to store your own data (e.g. buffer pointer),
- * and rely on pb_read to verify that no-body reads past bytes_left.
- *
- * 4) Your callback may be used with substreams, in which case bytes_left
- * is different than from the main stream. Don't use bytes_left to compute
- * any pointers.
+ * 2) You can use state to store your own data (e.g. buffer pointer),
+ * and rely on pb_read to verify that no-body reads past bytes_left.
+ * 3) Your callback may be used with substreams, in which case bytes_left
+ * is different than from the main stream. Don't use bytes_left to compute
+ * any pointers.
*/
-struct _pb_istream_t
+struct pb_istream_s
{
+#ifdef PB_BUFFER_ONLY
+ /* Callback pointer is not used in buffer-only configuration.
+ * Having an int pointer here allows binary compatibility but
+ * gives an error if someone tries to assign callback function.
+ */
+ int *callback;
+#else
bool (*callback)(pb_istream_t *stream, uint8_t *buf, size_t count);
+#endif
+
void *state; /* Free field for use by callback implementation */
size_t bytes_left;
+
+#ifndef PB_NO_ERRMSG
+ const char *errmsg;
+#endif
};
-pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
-bool pb_read(pb_istream_t *stream, uint8_t *buf, size_t count);
-
-/* Decode from stream to destination struct.
+/***************************
+ * Main decoding functions *
+ ***************************/
+
+/* Decode a single protocol buffers message from input stream into a C structure.
* Returns true on success, false on any failure.
* The actual struct pointed to by dest must match the description in fields.
+ * Callback fields of the destination structure must be initialized by caller.
+ * All other fields will be initialized by this function.
+ *
+ * Example usage:
+ * MyMessage msg = {};
+ * uint8_t buffer[64];
+ * pb_istream_t stream;
+ *
+ * // ... read some data into buffer ...
+ *
+ * stream = pb_istream_from_buffer(buffer, count);
+ * pb_decode(&stream, MyMessage_fields, &msg);
*/
bool pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
-/* --- Helper functions ---
- * You may want to use these from your caller or callbacks.
+/* Same as pb_decode, except does not initialize the destination structure
+ * to default values. This is slightly faster if you need no default values
+ * and just do memset(struct, 0, sizeof(struct)) yourself.
+ *
+ * This can also be used for 'merging' two messages, i.e. update only the
+ * fields that exist in the new message.
+ *
+ * Note: If this function returns with an error, it will not release any
+ * dynamically allocated fields. You will need to call pb_release() yourself.
+ */
+bool pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+
+/* Same as pb_decode, except expects the stream to start with the message size
+ * encoded as varint. Corresponds to parseDelimitedFrom() in Google's
+ * protobuf API.
*/
+bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+#ifdef PB_ENABLE_MALLOC
+/* Release any allocated pointer fields. If you use dynamic allocation, you should
+ * call this for any successfully decoded message when you are done with it. If
+ * pb_decode() returns with an error, the message is already released.
+ */
+void pb_release(const pb_field_t fields[], void *dest_struct);
+#endif
+
+
+/**************************************
+ * Functions for manipulating streams *
+ **************************************/
+
+/* Create an input stream for reading from a memory buffer.
+ *
+ * Alternatively, you can use a custom stream that reads directly from e.g.
+ * a file or a network socket.
+ */
+pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
+
+/* Function to read from a pb_istream_t. You can use this if you need to
+ * read some custom header data, or to read data in field callbacks.
+ */
+bool pb_read(pb_istream_t *stream, uint8_t *buf, size_t count);
+
+
+/************************************************
+ * Helper functions for writing field callbacks *
+ ************************************************/
+
+/* Decode the tag for the next field in the stream. Gives the wire type and
+ * field tag. At end of the message, returns false and sets eof to true. */
bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof);
+
+/* Skip the field payload data, given the wire type. */
bool pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type);
+/* Decode an integer in the varint format. This works for bool, enum, int32,
+ * int64, uint32 and uint64 field types. */
bool pb_decode_varint(pb_istream_t *stream, uint64_t *dest);
-bool pb_skip_varint(pb_istream_t *stream);
-bool pb_skip_string(pb_istream_t *stream);
+/* Decode an integer in the zig-zagged svarint format. This works for sint32
+ * and sint64. */
+bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest);
-/* --- Field decoders ---
- * Each decoder takes stream and field description, and a pointer to the field
- * in the destination struct (dest = struct_addr + field->data_offset).
- * For arrays, these functions are called repeatedly.
- */
+/* Decode a fixed32, sfixed32 or float value. You need to pass a pointer to
+ * a 4-byte wide C variable. */
+bool pb_decode_fixed32(pb_istream_t *stream, void *dest);
-bool pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest);
-bool pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
-bool pb_dec_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest);
-bool pb_dec_fixed64(pb_istream_t *stream, const pb_field_t *field, void *dest);
+/* Decode a fixed64, sfixed64 or double value. You need to pass a pointer to
+ * a 8-byte wide C variable. */
+bool pb_decode_fixed64(pb_istream_t *stream, void *dest);
-bool pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
-bool pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest);
-bool pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest);
+/* Make a limited-length substream for reading a PB_WT_STRING field. */
+bool pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
#endif
Code Review / apps / agl-service-can-low-level.git / blobdiff