From 9116c697f845e7ca215628029800c36f7dfbfaee Mon Sep 17 00:00:00 2001 From: Joshua Haberman Date: Fri, 15 Jan 2010 18:12:28 -0800 Subject: upb_parser -> upb_decoder --- src/upb_parse.c | 507 -------------------------------------------------------- 1 file changed, 507 deletions(-) delete mode 100644 src/upb_parse.c (limited to 'src/upb_parse.c') diff --git a/src/upb_parse.c b/src/upb_parse.c deleted file mode 100644 index be22203..0000000 --- a/src/upb_parse.c +++ /dev/null @@ -1,507 +0,0 @@ -/* - * upb - a minimalist implementation of protocol buffers. - * - * Copyright (c) 2008-2009 Joshua Haberman. See LICENSE for details. - */ - -#include "upb_parse.h" - -#include -#include -#include -#include "upb_def.h" - -/* Functions to read wire values. *********************************************/ - -// These functions are internal to the parser, but might be moved into an -// internal header file if we at some point in the future opt to do code -// generation, because the generated code would want to inline these functions. -// The same applies to the functions to read .proto values below. - -const uint8_t *upb_get_v_uint64_t_full(const uint8_t *buf, const uint8_t *end, - uint64_t *val, - struct upb_status *status); - -// Gets a varint (wire type: UPB_WIRE_TYPE_VARINT). -INLINE const uint8_t *upb_get_v_uint64_t(const uint8_t *buf, const uint8_t *end, - uint64_t *val, - struct upb_status *status) -{ - // We inline this common case (1-byte varints), if that fails we dispatch to - // the full (non-inlined) version. - if((*buf & 0x80) == 0) { - *val = *buf & 0x7f; - return buf + 1; - } else { - return upb_get_v_uint64_t_full(buf, end, val, status); - } -} - -// Gets a varint -- called when we only need 32 bits of it. Note that a 32-bit -// varint is not a true wire type. -INLINE const uint8_t *upb_get_v_uint32_t(const uint8_t *buf, const uint8_t *end, - uint32_t *val, - struct upb_status *status) -{ - uint64_t val64; - const uint8_t *ret = upb_get_v_uint64_t(buf, end, &val64, status); - *val = (uint32_t)val64; // Discard the high bits. - return ret; -} - -// Gets a fixed-length 32-bit integer (wire type: UPB_WIRE_TYPE_32BIT). -INLINE const uint8_t *upb_get_f_uint32_t(const uint8_t *buf, const uint8_t *end, - uint32_t *val, struct upb_status *status) -{ - const uint8_t *uint32_end = buf + sizeof(uint32_t); - if(uint32_end > end) { - status->code = UPB_STATUS_NEED_MORE_DATA; - return end; - } -#if UPB_UNALIGNED_READS_OK - *val = *(uint32_t*)buf; -#else -#define SHL(val, bits) ((uint32_t)val << bits) - *val = SHL(buf[0], 0) | SHL(buf[1], 8) | SHL(buf[2], 16) | SHL(buf[3], 24); -#undef SHL -#endif - return uint32_end; -} - -// Gets a fixed-length 64-bit integer (wire type: UPB_WIRE_TYPE_64BIT). -INLINE const uint8_t *upb_get_f_uint64_t(const uint8_t *buf, const uint8_t *end, - uint64_t *val, - struct upb_status *status) -{ - const uint8_t *uint64_end = buf + sizeof(uint64_t); - if(uint64_end > end) { - status->code = UPB_STATUS_NEED_MORE_DATA; - return end; - } -#if UPB_UNALIGNED_READS_OK - *val = *(uint64_t*)buf; -#else -#define SHL(val, bits) ((uint64_t)val << bits) - *val = SHL(buf[0], 0) | SHL(buf[1], 8) | SHL(buf[2], 16) | SHL(buf[3], 24) | - SHL(buf[4], 32) | SHL(buf[5], 40) | SHL(buf[6], 48) | SHL(buf[7], 56); -#undef SHL -#endif - return uint64_end; -} - -INLINE const uint8_t *upb_skip_v_uint64_t(const uint8_t *buf, - const uint8_t *end, - struct upb_status *status) -{ - const uint8_t *const maxend = buf + 10; - uint8_t last = 0x80; - for(; buf < (uint8_t*)end && (last & 0x80); buf++) - last = *buf; - - if(buf >= end && buf <= maxend && (last & 0x80)) { - status->code = UPB_STATUS_NEED_MORE_DATA; - buf = end; - } else if(buf > maxend) { - status->code = UPB_ERROR_UNTERMINATED_VARINT; - buf = end; - } - return buf; -} - -INLINE const uint8_t *upb_skip_f_uint32_t(const uint8_t *buf, - const uint8_t *end, - struct upb_status *status) -{ - const uint8_t *uint32_end = buf + sizeof(uint32_t); - if(uint32_end > end) { - status->code = UPB_STATUS_NEED_MORE_DATA; - return end; - } - return uint32_end; -} - -INLINE const uint8_t *upb_skip_f_uint64_t(const uint8_t *buf, - const uint8_t *end, - struct upb_status *status) -{ - const uint8_t *uint64_end = buf + sizeof(uint64_t); - if(uint64_end > end) { - status->code = UPB_STATUS_NEED_MORE_DATA; - return end; - } - return uint64_end; -} - -/* Functions to read .proto values. *******************************************/ - -// Performs zig-zag decoding, which is used by sint32 and sint64. -INLINE int32_t upb_zzdec_32(uint32_t n) { return (n >> 1) ^ -(int32_t)(n & 1); } -INLINE int64_t upb_zzdec_64(uint64_t n) { return (n >> 1) ^ -(int64_t)(n & 1); } - -// Use macros to define a set of two functions for each .proto type: -// -// // Reads and converts a .proto value from buf, placing it in d. -// // "end" indicates the end of the current buffer (if the buffer does -// // not contain the entire value UPB_STATUS_NEED_MORE_DATA is returned). -// // On success, a pointer will be returned to the first byte that was -// // not consumed. -// const uint8_t *upb_get_INT32(const uint8_t *buf, const uint8_t *end, -// int32_t *d, struct upb_status *status); -// -// // Given an already read wire value s (source), convert it to a .proto -// // value and return it. -// int32_t upb_wvtov_INT32(uint32_t s); -// -// These are the most efficient functions to call if you want to decode a value -// for a known type. - -#define WVTOV(type, wire_t, val_t) \ - INLINE val_t upb_wvtov_ ## type(wire_t s) - -#define GET(type, v_or_f, wire_t, val_t, member_name) \ - INLINE const uint8_t *upb_get_ ## type(const uint8_t *buf, const uint8_t *end, \ - val_t *d, struct upb_status *status) { \ - wire_t tmp = 0; \ - const uint8_t *ret = upb_get_ ## v_or_f ## _ ## wire_t(buf, end, &tmp, status); \ - *d = upb_wvtov_ ## type(tmp); \ - return ret; \ - } - -#define T(type, v_or_f, wire_t, val_t, member_name) \ - WVTOV(type, wire_t, val_t); /* prototype for GET below */ \ - GET(type, v_or_f, wire_t, val_t, member_name) \ - WVTOV(type, wire_t, val_t) - -T(INT32, v, uint32_t, int32_t, int32) { return (int32_t)s; } -T(INT64, v, uint64_t, int64_t, int64) { return (int64_t)s; } -T(UINT32, v, uint32_t, uint32_t, uint32) { return s; } -T(UINT64, v, uint64_t, uint64_t, uint64) { return s; } -T(SINT32, v, uint32_t, int32_t, int32) { return upb_zzdec_32(s); } -T(SINT64, v, uint64_t, int64_t, int64) { return upb_zzdec_64(s); } -T(FIXED32, f, uint32_t, uint32_t, uint32) { return s; } -T(FIXED64, f, uint64_t, uint64_t, uint64) { return s; } -T(SFIXED32, f, uint32_t, int32_t, int32) { return (int32_t)s; } -T(SFIXED64, f, uint64_t, int64_t, int64) { return (int64_t)s; } -T(BOOL, v, uint32_t, bool, _bool) { return (bool)s; } -T(ENUM, v, uint32_t, int32_t, int32) { return (int32_t)s; } -T(DOUBLE, f, uint64_t, double, _double) { - union upb_value v; - v.uint64 = s; - return v._double; -} -T(FLOAT, f, uint32_t, float, _float) { - union upb_value v; - v.uint32 = s; - return v._float; -} - -#undef WVTOV -#undef GET -#undef T - -// Parses a tag, places the result in *tag. -INLINE const uint8_t *parse_tag(const uint8_t *buf, const uint8_t *end, - struct upb_tag *tag, struct upb_status *status) -{ - uint32_t tag_int; - const uint8_t *ret = upb_get_v_uint32_t(buf, end, &tag_int, status); - tag->wire_type = (upb_wire_type_t)(tag_int & 0x07); - tag->field_number = tag_int >> 3; - return ret; -} - - -/** - * Parses a 64-bit varint that is known to be >= 2 bytes (the inline version - * handles 1 and 2 byte varints). - */ -const uint8_t *upb_get_v_uint64_t_full(const uint8_t *buf, const uint8_t *end, - uint64_t *val, struct upb_status *status) -{ - const uint8_t *const maxend = buf + 10; - uint8_t last = 0x80; - *val = 0; - int bitpos; - - for(bitpos = 0; buf < (uint8_t*)end && (last & 0x80); buf++, bitpos += 7) - *val |= ((uint64_t)((last = *buf) & 0x7F)) << bitpos; - - if(buf >= end && buf <= maxend && (last & 0x80)) { - upb_seterr(status, UPB_STATUS_NEED_MORE_DATA, - "Provided data ended in the middle of a varint.\n"); - buf = end; - } else if(buf > maxend) { - upb_seterr(status, UPB_ERROR_UNTERMINATED_VARINT, - "Varint was unterminated after 10 bytes.\n"); - buf = end; - } - - return buf; -} - -const uint8_t *upb_parse_wire_value(uint8_t *buf, uint8_t *end, - upb_wire_type_t wt, - union upb_wire_value *wv, - struct upb_status *status) -{ - switch(wt) { - case UPB_WIRE_TYPE_VARINT: - return upb_get_v_uint64_t(buf, end, &wv->varint, status); - case UPB_WIRE_TYPE_64BIT: - return upb_get_f_uint64_t(buf, end, &wv->_64bit, status); - case UPB_WIRE_TYPE_32BIT: - return upb_get_f_uint32_t(buf, end, &wv->_32bit, status); - default: - status->code = UPB_STATUS_ERROR; // Doesn't handle delimited, groups. - return end; - } -} - -/** - * Advances buf past the current wire value (of type wt), saving the result in - * outbuf. - */ -static const uint8_t *skip_wire_value(const uint8_t *buf, const uint8_t *end, - upb_wire_type_t wt, - struct upb_status *status) -{ - switch(wt) { - case UPB_WIRE_TYPE_VARINT: - return upb_skip_v_uint64_t(buf, end, status); - case UPB_WIRE_TYPE_64BIT: - return upb_skip_f_uint64_t(buf, end, status); - case UPB_WIRE_TYPE_32BIT: - return upb_skip_f_uint32_t(buf, end, status); - case UPB_WIRE_TYPE_START_GROUP: - // TODO: skip to matching end group. - case UPB_WIRE_TYPE_END_GROUP: - return buf; - default: - status->code = UPB_STATUS_ERROR; - return end; - } -} - -static const uint8_t *upb_parse_value(const uint8_t *buf, const uint8_t *end, - upb_field_type_t ft, - union upb_value_ptr v, - struct upb_status *status) -{ -#define CASE(t, member_name) \ - case UPB_TYPE(t): return upb_get_ ## t(buf, end, v.member_name, status); - - switch(ft) { - CASE(DOUBLE, _double) - CASE(FLOAT, _float) - CASE(INT32, int32) - CASE(INT64, int64) - CASE(UINT32, uint32) - CASE(UINT64, uint64) - CASE(SINT32, int32) - CASE(SINT64, int64) - CASE(FIXED32, uint32) - CASE(FIXED64, uint64) - CASE(SFIXED32, int32) - CASE(SFIXED64, int64) - CASE(BOOL, _bool) - CASE(ENUM, int32) - default: return end; - } - -#undef CASE -} - -struct upb_parser_frame { - struct upb_msgdef *msgdef; - struct upb_fielddef *field; - size_t end_offset; // For groups, 0. -}; - -struct upb_parser { - // Immutable state of the parser. - struct upb_msgdef *toplevel_msgdef; - upb_sink *sink; - - // State pertaining to a particular parse (resettable). - // Stack entries store the offset where the submsg ends (for groups, 0). - struct upb_parser_frame stack[UPB_MAX_NESTING], *top, *limit; - size_t completed_offset; - void *udata; -}; - -upb_parser *upb_parser_new(struct upb_msgdef *msgdef) -{ - upb_parser *p = malloc(sizeof(*p)); - p->toplevel_msgdef = msgdef; - p->limit = &p->stack[UPB_MAX_NESTING]; - return p; -} - -void upb_parser_free(upb_parser *p) -{ - free(p); -} - -void upb_parser_reset(upb_parser *p, upb_sink *sink) -{ - p->top = p->stack; - p->completed_offset = 0; - p->sink = sink; - p->top->msgdef = p->toplevel_msgdef; - // The top-level message is not delimited (we can keep receiving data for it - // indefinitely), so we treat it like a group. - p->top->end_offset = 0; -} - -static const void *get_msgend(upb_parser *p, const uint8_t *start) -{ - if(p->top->end_offset > 0) - return start + (p->top->end_offset - p->completed_offset); - else - return (void*)UINTPTR_MAX; // group. -} - -static bool isgroup(const void *submsg_end) -{ - return submsg_end == (void*)UINTPTR_MAX; -} - -extern upb_wire_type_t upb_expected_wire_types[]; -// Returns true if wt is the correct on-the-wire type for ft. -INLINE bool upb_check_type(upb_wire_type_t wt, upb_field_type_t ft) { - // This doesn't currently support packed arrays. - return upb_type_info[ft].expected_wire_type == wt; -} - - -/** - * Pushes a new stack frame for a submessage with the given len (which will - * be zero if the submessage is a group). - */ -static const uint8_t *push(upb_parser *p, const uint8_t *start, - uint32_t submsg_len, struct upb_fielddef *f, - struct upb_status *status) -{ - p->top->field = f; - p->top++; - if(p->top >= p->limit) { - upb_seterr(status, UPB_STATUS_ERROR, - "Nesting exceeded maximum (%d levels)\n", - UPB_MAX_NESTING); - return NULL; - } - struct upb_parser_frame *frame = p->top; - frame->end_offset = p->completed_offset + submsg_len; - frame->msgdef = upb_downcast_msgdef(f->def); - - upb_sink_onstart(p->sink, f); - return get_msgend(p, start); -} - -/** - * Pops a stack frame, returning a pointer for where the next submsg should - * end (or a pointer that is out of range for a group). - */ -static const void *pop(upb_parser *p, const uint8_t *start) -{ - p->top--; - upb_sink_onend(p->sink, p->top->field); - return get_msgend(p, start); -} - - -size_t upb_parser_parse(upb_parser *p, upb_strptr str, struct upb_status *status) -{ - // buf is our current offset, moves from start to end. - const uint8_t *buf = (uint8_t*)upb_string_getrobuf(str); - const uint8_t *const start = buf; // ptr equivalent of p->completed_offset - const uint8_t *const end = buf + upb_strlen(str); - - // When we have fully parsed a tag/value pair, we advance this. - const uint8_t *completed = buf; - - const uint8_t *submsg_end = get_msgend(p, start); - struct upb_msgdef *msgdef = p->top->msgdef; - upb_sink_status sink_status = UPB_SINK_CONTINUE; - - // We need to check the status of operations that can fail, but we do so as - // late as possible to avoid introducing branches that have to wait on - // (status->code) which must be loaded from memory. We must always check - // before calling a user callback. -#define CHECK_STATUS() do { if(!upb_ok(status)) goto err; } while(0) - - // Main loop: executed once per tag/field pair. - while(sink_status == UPB_SINK_CONTINUE && buf < end) { - // Parse/handle tag. - struct upb_tag tag; - buf = parse_tag(buf, end, &tag, status); - if(tag.wire_type == UPB_WIRE_TYPE_END_GROUP) { - CHECK_STATUS(); - if(!isgroup(submsg_end)) { - upb_seterr(status, UPB_STATUS_ERROR, "End group seen but current " - "message is not a group, byte offset: %zd", - p->completed_offset + (completed - start)); - goto err; - } - submsg_end = pop(p, start); - msgdef = p->top->msgdef; - completed = buf; - continue; - } - - // Look up field by tag number. - struct upb_fielddef *f = upb_msg_itof(msgdef, tag.field_number); - - // Parse/handle field. - if(tag.wire_type == UPB_WIRE_TYPE_DELIMITED) { - int32_t delim_len; - buf = upb_get_INT32(buf, end, &delim_len, status); - CHECK_STATUS(); // Checking parse_tag() and upb_get_INT32(). - const uint8_t *delim_end = buf + delim_len; - if(f && f->type == UPB_TYPE(MESSAGE)) { - submsg_end = push(p, start, delim_end - start, f, status); - msgdef = p->top->msgdef; - } else { - if(f && upb_isstringtype(f->type)) { - int32_t str_start = buf - start; - sink_status = - upb_sink_onstr(p->sink, f, str, str_start, str_start + delim_len); - } // else { TODO: packed arrays } - // If field was not found, it is skipped silently. - buf = delim_end; // Could be >end. - } - } else { - if(!f || !upb_check_type(tag.wire_type, f->type)) { - buf = skip_wire_value(buf, end, tag.wire_type, status); - } else if (f->type == UPB_TYPE(GROUP)) { - submsg_end = push(p, start, 0, f, status); - msgdef = p->top->msgdef; - } else { - union upb_value val; - buf = upb_parse_value(buf, end, f->type, upb_value_addrof(&val), - status); - CHECK_STATUS(); // Checking upb_parse_value(). - sink_status = upb_sink_onvalue(p->sink, f, val); - } - } - CHECK_STATUS(); - - while(buf >= submsg_end) { - if(buf > submsg_end) { - upb_seterr(status, UPB_STATUS_ERROR, "Expected submsg end offset " - "did not lie on a tag/value boundary."); - goto err; - } - submsg_end = pop(p, start); - msgdef = p->top->msgdef; - } - // while(buf < p->packed_end) { TODO: packed arrays } - completed = buf; - } - - size_t read; -err: - read = (char*)completed - (char*)start; - p->completed_offset += read; - return read; -} -- cgit v1.2.3