From 976303d04d3bc2cad0afd5e3d364264783da56c2 Mon Sep 17 00:00:00 2001 From: David Levine Date: Tue, 25 Dec 2012 11:57:31 -0600 Subject: [PATCH] Remove stdio internals manipulation in sbr/m_getfld.c Replaced all the stdio buffer access in sbr/m_getfld.c with a single call to fread() and then some almost straightforward buffer manipulations. This commit is ported to mmh. --- sbr/m_getfld.c | 311 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 156 insertions(+), 155 deletions(-) diff --git a/sbr/m_getfld.c b/sbr/m_getfld.c index 1cc041b..108af13 100644 --- a/sbr/m_getfld.c +++ b/sbr/m_getfld.c @@ -149,16 +149,73 @@ static int edelimlen; static int (*eom_action)(int) = NULL; -#ifdef _FSTDIO -# define _ptr _p /* Gag */ -# define _cnt _r /* Retch */ -# define _filbuf __srget /* Puke */ -# define DEFINED__FILBUF_TO_SOMETHING_SPECIFIC -#endif +/* +** This replaces the old approach, which included direct access to +** stdio internals. It uses one fread() to load a buffer that we +** manage. +*/ +#define MSG_INPUT_SIZE 8192 +static struct m_getfld_buffer { + unsigned char msg_buf[2 * MSG_INPUT_SIZE]; + unsigned char *readpos; + unsigned char *end; /* One past the last character read in. */ +} m; + +static void +setup_buffer(FILE *iob, struct m_getfld_buffer *m) +{ + /* + ** Rely on Restrictions that m_getfld() calls on different file + ** streams are not interleaved, and no other file stream read + ** methods are used. And, the first call to m_getfld (), etc., on + ** a stream always reads at least 1 byte. + ** I don't think it's necessary to use ftello() because we just + ** need to determine whether the current offset is 0 or not. + */ + if (ftell(iob) == 0) { + /* A new file stream, so reset the buffer state. */ + m->readpos = m->end = m->msg_buf; + } +} + +static size_t +read_more(struct m_getfld_buffer *m, FILE *iob) +{ + size_t num_read; + + /* Move any leftover at the end of buf to the beginning. */ + if (m->end > m->readpos) { + memmove(m->msg_buf, m->readpos, m->end - m->readpos); + } + m->readpos = m->msg_buf + (m->end - m->readpos); + num_read = fread(m->readpos, 1, MSG_INPUT_SIZE, iob); + m->end = m->readpos + num_read; + + return num_read; +} + +static int +Getc(FILE *iob) +{ + if (m.end - m.readpos < 1) { + if (read_more(&m, iob) == 0) { + /* + ** Pretend that we read a character. + ** That's what stdio does. + */ + ++m.readpos; + return EOF; + } + } + return (m.readpos < m.end) ? *m.readpos++ : EOF; +} + +static int +Ungetc(int c, FILE *iob) +{ + return (m.readpos == m.msg_buf) ? EOF : (*--m.readpos = c); +} -#ifndef DEFINED__FILBUF_TO_SOMETHING_SPECIFIC -extern int _filbuf(FILE*); -#endif int @@ -166,9 +223,11 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, int bufsz, FILE *iob) { unsigned char *bp, *cp, *ep, *sp; - int cnt, c, i, j; + int cnt, c, i, j, k; + + setup_buffer(iob, &m); - if ((c = getc(iob)) < 0) { + if ((c = Getc(iob)) < 0) { msg_count = 0; *buf = 0; return FILEEOF; @@ -176,10 +235,10 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, if (eom(c, iob)) { if (! eom_action) { /* flush null messages */ - while ((c = getc(iob)) >= 0 && eom(c, iob)) + while ((c = Getc(iob)) >= 0 && eom(c, iob)) ; if (c >= 0) - ungetc(c, iob); + Ungetc(c, iob); } msg_count = 0; *buf = 0; @@ -192,16 +251,16 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, case FLD: if (c == '\n' || c == '-') { /* we hit the header/body separator */ - while (c != '\n' && (c = getc(iob)) >= 0) + while (c != '\n' && (c = Getc(iob)) >= 0) ; - if (c < 0 || (c = getc(iob)) < 0 || eom(c, iob)) { + if (c < 0 || (c = Getc(iob)) < 0 || eom(c, iob)) { if (!eom_action) { /* flush null messages */ - while ((c = getc(iob)) >= 0 && eom(c, iob)) + while ((c = Getc(iob)) >= 0 && eom(c, iob)) ; if (c >= 0) - ungetc(c, iob); + Ungetc(c, iob); } msg_count = 0; *buf = 0; @@ -218,47 +277,28 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, cp = name; i = NAMESZ - 1; for (;;) { -#ifdef LINUX_STDIO - bp = sp = (unsigned char *) iob->_IO_read_ptr - 1; - j = (cnt = ((long) iob->_IO_read_end - - (long) iob->_IO_read_ptr) + 1) < i ? cnt : i; -#elif defined(__DragonFly__) - bp = sp = (unsigned char *) ((struct __FILE_public *)iob)->_p - 1; - j = (cnt = ((struct __FILE_public *)iob)->_r+1) < i ? cnt : i; -#else - bp = sp = (unsigned char *) iob->_ptr - 1; - j = (cnt = iob->_cnt+1) < i ? cnt : i; -#endif + /* Store current pos, ungetting the last char. */ + bp = sp = (unsigned char *) m.readpos - 1; + j = ((cnt = m.end - m.readpos + 1) < i) ? cnt : i; + while (--j >= 0 && (c = *bp++) != ':' && c != '\n') *cp++ = c; j = bp - sp; if ((cnt -= j) <= 0) { -#ifdef LINUX_STDIO - iob->_IO_read_ptr = iob->_IO_read_end; - if (__underflow(iob) == EOF) { -#elif defined(__DragonFly__) - if (__srget(iob) == EOF) { -#else - if (_filbuf(iob) == EOF) { -#endif + /* + ** Used to explicitly force refill of the + ** buffer here, but Getc() will do that + ** if necessary. + */ + if (Getc (iob) == EOF) { *cp = *buf = 0; advise(NULL, "eof encountered in field \"%s\"", name); return FMTERR; } -#ifdef LINUX_STDIO - iob->_IO_read_ptr++; /* NOT automatic in __underflow()! */ -#endif } else { -#ifdef LINUX_STDIO - iob->_IO_read_ptr = bp + 1; -#elif defined(__DragonFly__) - ((struct __FILE_public *)iob)->_p = bp + 1; - ((struct __FILE_public *)iob)->_r = cnt - 1; -#else - iob->_ptr = bp + 1; - iob->_cnt = cnt - 1; -#endif + /* Restore the current offset. */ + m.readpos = bp + 1; } if (c == ':') break; @@ -312,7 +352,13 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, ** that should be harmless enough, right? ** This is a corrupt message anyway. */ - fseek(iob, ftell(iob) - 2, SEEK_SET); + /* emulates: fseek(iob, ftell(iob) -(-2 + cnt + 1), SEEK_SET) */ + m.readpos += cnt - 1; + /* + ** Reset file stream position so caller, + ** e.g., get_content, can use ftell(), etc. + */ + fseek(iob, -cnt - 1, SEEK_CUR); return BODY; } if ((i -= j) <= 0) { @@ -336,16 +382,9 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, */ cp = buf; i = bufsz-1; for (;;) { -#ifdef LINUX_STDIO - cnt = (long) iob->_IO_read_end - (long) iob->_IO_read_ptr; - bp = (unsigned char *) --iob->_IO_read_ptr; -#elif defined(__DragonFly__) - cnt = ((struct __FILE_public *)iob)->_r++; - bp = (unsigned char *) --((struct __FILE_public *)iob)->_p; -#else - cnt = iob->_cnt++; - bp = (unsigned char *) --iob->_ptr; -#endif + /* Set and save the current pos and update cnt. */ + cnt = m.end - m.readpos; + bp = --m.readpos; c = cnt < i ? cnt : i; while ((ep = locc( c, bp, '\n' ))) { /* @@ -353,21 +392,13 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, ** return. */ if ((j = *++ep) != ' ' && j != '\t') { -#ifdef LINUX_STDIO - j = ep - (unsigned char *) iob->_IO_read_ptr; - memcpy(cp, iob->_IO_read_ptr, j); - iob->_IO_read_ptr = ep; -#elif defined(__DragonFly__) - j = ep - (unsigned char *) ((struct __FILE_public *)iob)->_p; - memcpy(cp, ((struct __FILE_public *)iob)->_p, j); - ((struct __FILE_public *)iob)->_p = ep; - ((struct __FILE_public *)iob)->_r -= j; -#else - j = ep - (unsigned char *) iob->_ptr; - memcpy(cp, iob->_ptr, j); - iob->_ptr = ep; - iob->_cnt -= j; -#endif + /* + ** Save the text and update the + ** current position. + */ + j = ep - m.readpos; + memcpy (cp, m.readpos, j); + m.readpos = ep; cp += j; state = FLD; goto finish; @@ -379,64 +410,34 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, ** end of input or dest buffer - copy what ** we've found. */ -#ifdef LINUX_STDIO - c += bp - (unsigned char *) iob->_IO_read_ptr; - memcpy(cp, iob->_IO_read_ptr, c); -#elif defined(__DragonFly__) - c += bp - (unsigned char *) ((struct __FILE_public *)iob)->_p; - memcpy(cp, ((struct __FILE_public *)iob)->_p, c); -#else - c += bp - (unsigned char *) iob->_ptr; - memcpy(cp, iob->_ptr, c); -#endif - i -= c; - cp += c; + c += bp - m.readpos; + for (k = 0; k < c; ++k, --i) { + *cp++ = Getc (iob); + } if (i <= 0) { /* the dest buffer is full */ -#ifdef LINUX_STDIO - iob->_IO_read_ptr += c; -#elif defined(__DragonFly__) - ((struct __FILE_public *)iob)->_r -= c; - ((struct __FILE_public *)iob)->_p += c; -#else - iob->_cnt -= c; - iob->_ptr += c; -#endif state = FLDPLUS; break; } /* ** There's one character left in the input - ** buffer. Copy it & fill the buffer. - ** If the last char was a newline and the - ** next char is not whitespace, this is - ** the end of the field. Otherwise loop. + ** buffer. Copy it & fill the buffer (that + ** fill used to be explicit, but now Getc() + ** does it). If the last char was a newline + ** and the next char is not whitespace, this + ** is the end of the field. Otherwise loop. */ --i; -#ifdef LINUX_STDIO - *cp++ = j = *(iob->_IO_read_ptr + c); - iob->_IO_read_ptr = iob->_IO_read_end; - c = __underflow(iob); - iob->_IO_read_ptr++; /* NOT automatic! */ -#elif defined(__DragonFly__) - *cp++ =j = *(((struct __FILE_public *)iob)->_p + c); - c = __srget(iob); -#else - *cp++ = j = *(iob->_ptr + c); - c = _filbuf(iob); -#endif + *cp++ = j = Getc(iob); + c = Getc(iob); if (c == EOF || ((j == '\0' || j == '\n') && c != ' ' && c != '\t')) { if (c != EOF) { -#ifdef LINUX_STDIO - --iob->_IO_read_ptr; -#elif defined(__DragonFly__) - --((struct __FILE_public *)iob)->_p; - ++((struct __FILE_public *)iob)->_r; -#else - --iob->_ptr; - ++iob->_cnt; -#endif + /* + ** Put the character back for + ** the next call. + */ + --m.readpos; } state = FLD; break; @@ -454,17 +455,10 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, ** don't add an eos. */ i = (bufsz < 0) ? -bufsz : bufsz-1; -#ifdef LINUX_STDIO - bp = (unsigned char *) --iob->_IO_read_ptr; - cnt = (long) iob->_IO_read_end - (long) iob->_IO_read_ptr; -#elif defined(__DragonFly__) - bp = (unsigned char *) --((struct __FILE_public *)iob)->_p; - cnt = ++((struct __FILE_public *)iob)->_r; -#else - bp = (unsigned char *) --iob->_ptr; - cnt = ++iob->_cnt; -#endif - c = (cnt < i ? cnt : i); + /* Back up and store the current position and update cnt. */ + bp = --m.readpos; + cnt = m.end - m.readpos; + c = (cnt < i) ? cnt : i; if (ismbox && c > 1) { /* ** packed maildrop - only take up to the (possible) @@ -547,15 +541,8 @@ m_getfld(int state, unsigned char *name, unsigned char *buf, } } memcpy( buf, bp, c ); -#ifdef LINUX_STDIO - iob->_IO_read_ptr += c; -#elif defined(__DragonFly__) - ((struct __FILE_public *)iob)->_r -= c; - ((struct __FILE_public *)iob)->_p += c; -#else - iob->_cnt -= c; - iob->_ptr += c; -#endif + /* Advance the current position to reflect the copy out. */ + m.readpos += c; if (bufsz < 0) { msg_count = c; return (state); @@ -581,11 +568,13 @@ thisisanmbox(FILE *iob) char *cp; char *delimstr; - c = getc(iob); + setup_buffer(iob, &m); + + c = Getc(iob); if (feof(iob)) { return; } - ungetc(c, iob); + Ungetc(c, iob); /* ** Figure out what the message delimitter string is for this @@ -598,8 +587,12 @@ thisisanmbox(FILE *iob) ** say the style is MBOX and eat the rest of the line. Otherwise ** abort. */ - - if (fread(text, sizeof(*text), 5, iob) != 5) { + for (c=0, cp=text; c<5; ++c, ++cp) { + if ((*cp = Getc(iob)) == EOF) { + break; + } + } + if (c != 5) { adios(EX_IOERR, NULL, "Read error"); } if (strncmp(text, "From ", 5)!=0) { @@ -607,7 +600,7 @@ thisisanmbox(FILE *iob) } ismbox = TRUE; delimstr = "\nFrom "; - while ((c = getc(iob)) != '\n' && c >= 0) { + while ((c = Getc(iob)) != '\n' && c >= 0) { continue; } c = strlen(delimstr); @@ -620,8 +613,9 @@ thisisanmbox(FILE *iob) edelimlen = c - 1; strcpy(msg_delim, delimstr); delimend = (unsigned char *)msg_delim + edelimlen; - if (edelimlen <= 1) + if (edelimlen <= 1) { adios(EX_DATAERR, NULL, "maildrop delimiter must be at least 2 bytes"); + } /* ** build a Boyer-Moore end-position map for the matcher in m_getfld. ** N.B. - we don't match just the first char (since it's the newline @@ -630,8 +624,9 @@ thisisanmbox(FILE *iob) */ pat_map = (unsigned char **) calloc(256, sizeof(unsigned char *)); - for (cp = (char *) fdelim + 1; cp < (char *) delimend; cp++ ) + for (cp = (char *) fdelim + 1; cp < (char *) delimend; cp++) { pat_map[(unsigned char)*cp] = (unsigned char *) cp; + } } @@ -642,27 +637,33 @@ thisisanmbox(FILE *iob) static int m_Eom(int c, FILE *iob) { - long pos = 0L; + unsigned char *pos; int i; char text[10]; + char *cp; - pos = ftell(iob); - if ((i = fread(text, sizeof *text, edelimlen, iob)) != edelimlen || + pos = m.readpos; /* ftell */ + for (i=0, cp=text; i= 0) { + while ((c = Getc(iob)) != '\n' && c >= 0) { continue; } } -- 1.7.10.4