From 2d21601d477dfc242d31acabdad119a56d2b7945 Mon Sep 17 00:00:00 2001 From: Joshua Haberman Date: Mon, 29 Jun 2009 17:54:50 -0700 Subject: Reworked low-level parsing: smaller, safer. --- upb_parse.h | 40 +++++++++++----------------------------- 1 file changed, 11 insertions(+), 29 deletions(-) (limited to 'upb_parse.h') diff --git a/upb_parse.h b/upb_parse.h index 4be272a..fbc5898 100644 --- a/upb_parse.h +++ b/upb_parse.h @@ -29,31 +29,14 @@ void upb_parse_state_init(struct upb_parse_state *state, size_t udata_size); void upb_parse_state_free(struct upb_parse_state *state); /* The callback that is called immediately after a tag has been parsed. The - * client uses it to decide if it wants to process this value or skip it. If - * it wants to process it, it must determine its specific .proto type (at this - * point we only know its wire type) and verify that it matches the wire type. - * The client will then return the .proto type. To skip the value, the client - * should return 0 (which is not a valid .proto type). + * client must either advance the stream beyond the corresponding value or + * return an error to indicate that the stream should rewind to before the + * tag. * - * The client can set user_field_desc to a record describing this field -- this - * pointer will be supplied to the value callback (for simple values) or the - * submsg_start callback (for submessages). - * - * TODO: there needs to be a way to skip a delimited field while still knowing - * its offset and length. That could be through this callback or it could be a - * separate callback. */ -typedef upb_field_type_t (*upb_tag_cb)(struct upb_parse_state *s, - struct upb_tag *tag, - void **user_field_desc); - -/* The callback that is called for individual values. This callback is only - * called when the previously invoked tag_cb has returned nonzero. It receives - * the parsed and converted value as well as the user_field_desc that was set - * by the tag_cb. Note that this function can be called several times in a row - * (ie. with no intervening tag_cb) in the case of packed arrays. For string - * data (bytes and string) str points to the beginning of the string. */ -typedef void (*upb_value_cb)(struct upb_parse_state *s, union upb_value *v, - void *str, void *user_field_desc); + * The client advances the stream beyond the corresponding value by either + * parsing the value or skipping it. */ +typedef upb_field_type_t (*upb_tag_cb)(void **buf, struct upb_parse_state *s, + struct upb_tag *tag); /* Callbacks that are called when a submessage begins and ends, respectively. * Both are called with the submessage's stack frame at the top of the stack. */ @@ -77,7 +60,6 @@ struct upb_parse_state { size_t packed_end_offset; /* 0 if not in a packed array. */ upb_field_type_t packed_type; upb_tag_cb tag_cb; - upb_value_cb value_cb; upb_submsg_start_cb submsg_start_cb; upb_submsg_end_cb submsg_end_cb; }; @@ -94,7 +76,7 @@ upb_status_t upb_parse(struct upb_parse_state *s, void *buf, size_t len, /* Parses a single tag from the character data starting at buf, and updates * buf to point one past the bytes that were consumed. buf will be incremented * by at most ten bytes. */ -upb_status_t upb_parse_tag(void **buf, struct upb_tag *tag); +upb_status_t upb_parse_tag(void **buf, size_t len, struct upb_tag *tag); extern upb_wire_type_t upb_expected_wire_types[]; /* Returns true if wt is the correct on-the-wire type for ft. */ @@ -106,19 +88,19 @@ INLINE bool upb_check_type(upb_wire_type_t wt, upb_field_type_t ft) { * caller must have previously checked that the wire type is appropriate for * this field type. For delimited data, buf is advanced to the beginning of * the delimited data, not the end. */ -upb_status_t upb_parse_value(void **buf, upb_field_type_t ft, +upb_status_t upb_parse_value(void **buf, size_t len, upb_field_type_t ft, union upb_value *value); /* Parses a wire value with the given type (which must have been obtained from * a tag that was just parsed) and adds the number of bytes that were consumed * to *offset. For delimited types, offset is advanced past the delimited * data. */ -upb_status_t upb_parse_wire_value(void *buf, size_t *offset, +upb_status_t upb_parse_wire_value(void *buf, size_t len, size_t *offset, upb_wire_type_t wt, union upb_wire_value *wv); /* Like the above, but discards the wire value instead of saving it. */ -upb_status_t upb_skip_wire_value(void *buf, size_t *offset, +upb_status_t upb_skip_wire_value(void *buf, size_t len, size_t *offset, upb_wire_type_t wt); #ifdef __cplusplus -- cgit v1.2.3