From 46a27c2f93cfc284ad64b21b7e1b179499b23bff Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Sun, 30 Dec 2007 00:13:07 +0000 Subject: r15750@tombo: nickm | 2007-12-29 19:12:51 -0500 Make HTTP-processing code in buffers.c faster: do not pull up 50K of text into the first chunk if the headers end earlier than that. svn:r13006 --- src/or/buffers.c | 93 ++++++++++++++++++++++---------------------------------- 1 file changed, 36 insertions(+), 57 deletions(-) diff --git a/src/or/buffers.c b/src/or/buffers.c index 729b987b4f..c99a550421 100644 --- a/src/or/buffers.c +++ b/src/or/buffers.c @@ -943,28 +943,32 @@ move_buf_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen) return cp; } -// #define BUFPOS -#ifdef BUFPOS +/** Internal structure: represents a position in a buffer. */ typedef struct buf_pos_t { - chunk_t *chunk; - int pos; - int pos_absolute; -}; + const chunk_t *chunk; /**< Which chunk are we pointing to? */ + int pos; /**< Which character inside the chunk's data are we pointing to? */ + int pos_absolute; /**< Which character inside the buffer are we pointing to? + */ +} buf_pos_t; +/** Initialize out to point to the first character of buf.*/ static void -buf_pos_init(buf_t *buf, buf_pos_t *out) +buf_pos_init(const buf_t *buf, buf_pos_t *out) { out->chunk = buf->head; out->pos = 0; out->pos_absolute = 0; } +/** Advance out to the first appearance of ch at the current + * position of out, or later. Return -1 if no instances are found; + * otherwise returns the absolute position of the character. */ static int -buf_find_pos_of_char(const buf_t *buf, char ch, buf_pos_t *out) +buf_find_pos_of_char(char ch, buf_pos_t *out) { - chunk_t *chunk; + const chunk_t *chunk; int offset = 0; - int pos = chunk->pos; + int pos = out->pos; for (chunk = out->chunk; chunk; chunk = chunk->next) { char *cp = memchr(chunk->data+pos, ch, chunk->datalen-pos); if (cp) { @@ -980,10 +984,12 @@ buf_find_pos_of_char(const buf_t *buf, char ch, buf_pos_t *out) return -1; } +/** Advance pos by a single character, if there are any more characters + * in the buffer. Returns 0 on sucess, -1 on failure. */ static INLINE int buf_pos_inc(buf_pos_t *pos) { - if (pos->pos == pos->chunk->datalen) { + if ((size_t)pos->pos == pos->chunk->datalen) { if (!pos->chunk->next) return -1; pos->chunk = pos->chunk->next; @@ -992,43 +998,46 @@ buf_pos_inc(buf_pos_t *pos) ++pos->pos; } ++pos->pos_absolute; + return 0; } +/** Return true iff the n-character string in s appears + * (verbatim) at pos. */ static int -buf_matches_at_pos(const buf_t *buf, const buf_pos_t *pos, const char *s, - int n) +buf_matches_at_pos(const buf_pos_t *pos, const char *s, int n) { buf_pos_t p; - memcpy(p, pos, sizeof(p)); + memcpy(&p, pos, sizeof(p)); while (n) { - char ch = p->chunk->data[p->pos]; + char ch = p.chunk->data[p.pos]; if (ch != *s) return 0; ++s; --n; - if (buf_pos_inc(p)<0) + if (buf_pos_inc(&p)<0) return 0; } return 1; } +/** Return the first position in buf at which the n-character + * string s occurs, or -1 if it does not occur. */ static int -buf_find_string_offset(const char *buf, const char *s, int n) +buf_find_string_offset(const buf_t *buf, const char *s, int n) { buf_pos_t pos; buf_pos_init(buf, &pos); - while (buf_find_pos_of_char(buf, *s, &pos) >= 0) { - if (buf_matches_at_pos(buf, pos, s, n)) { - return pos->pos_absolute; + while (buf_find_pos_of_char(*s, &pos) >= 0) { + if (buf_matches_at_pos(&pos, s, n)) { + return pos.pos_absolute; } else { - if (buf_pos_inc(pos)<0) + if (buf_pos_inc(&pos)<0) return -1; } } return -1; } -#endif /** There is a (possibly incomplete) http statement on buf, of the * form "\%s\\r\\n\\r\\n\%s", headers, body. (body may contain nuls.) @@ -1055,21 +1064,17 @@ fetch_from_buf_http(buf_t *buf, char **body_out, size_t *body_used, size_t max_bodylen, int force_complete) { - char *headers, *p, *body; + char *headers, *p; size_t headerlen, bodylen, contentlen; -#ifdef BUFPOS int crlf_offset; -#endif check(); if (!buf->head) return 0; headers = buf->head->data; - -#ifdef BUFPOS crlf_offset = buf_find_string_offset(buf, "\r\n\r\n", 4); - if (crlf_offset > max_headerlen || + if (crlf_offset > (int)max_headerlen || (crlf_offset < 0 && buf->datalen > max_headerlen)) { log_debug(LD_HTTP,"headers too long."); return -1; @@ -1077,37 +1082,11 @@ fetch_from_buf_http(buf_t *buf, log_debug(LD_HTTP,"headers not all here yet."); return 0; } - if (buf->head->datalen < crlf_offset + 4) + /* Okay, we have a full header. Make sure it all appears in the first + * chunk. */ + if ((int)buf->head->datalen < crlf_offset + 4) buf_pullup(buf, crlf_offset+4, 0); headerlen = crlf_offset + 4; - body = buf->data + headerlen; /*XXX020 unused. */ -#else - /* See if CRLFCRLF is already in the head chunk. If it is, we don't need - * to move or resize anything. */ - body = (char*) tor_memmem(buf->head->data, buf->head->datalen, - "\r\n\r\n", 4); - if (!body && buf->datalen > buf->head->datalen) { - size_t len_scanned = buf->head->datalen; - buf_pullup(buf, max_headerlen, 0); - headers = buf->head->data; - /* avoid searching the original part of the head chunk twice. */ - len_scanned = (len_scanned > 4) ? len_scanned - 4 : 0; - body = (char*) tor_memmem(buf->head->data + len_scanned, - buf->head->datalen - len_scanned, - "\r\n\r\n", 4); - } - - if (!body) { - if (buf->head->datalen >= max_headerlen) { - log_debug(LD_HTTP,"headers too long."); - return -1; - } - log_debug(LD_HTTP,"headers not all here yet."); - return 0; - } - body += 4; /* Skip the the CRLFCRLF */ - headerlen = body-headers; /* includes the CRLFCRLF */ -#endif bodylen = buf->datalen - headerlen; log_debug(LD_HTTP,"headerlen %d, bodylen %d.", (int)headerlen, (int)bodylen); -- cgit v1.2.3-54-g00ecf