mboxscan.c
20.9 KB
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/* GNU Mailutils -- a suite of utilities for electronic mail
Copyright (C) 1999, 2000, 2001, 2003, 2005, 2007, 2010 Free Software
Foundation, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library; if not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301 USA */
/* Mailbox Parsing. */
/* Credits to the c-client and its Authors
* The notorius c-client VALID() macro, was written by Mark Crispin.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef WITH_PTHREAD
# ifdef HAVE_PTHREAD_H
# define _XOPEN_SOURCE 500
# include <pthread.h>
# endif
#endif
#include <stdlib.h>
#include <mbox0.h>
/* Parsing.
The approach is to detect the "From " as start of a new message, give the
position of the header and scan until "\n" then set header_end, set body
position, scan until we it another "From " and set body_end.
************************************
This is a classic case of premature optimisation being the root of all
Evil(Donald E. Knuth). But I'm under "pressure" ;-) to come with
something "faster". I think it's wastefull to spend time to gain a few
seconds on 30Megs mailboxes ... but then again ... in computer time, 60
seconds, is eternity. If they use the event notification stuff to get
some headers/messages early ... it's like pissing in the wind(sorry don't
have the english equivalent). The worst is progress_bar it should be ...
&*($^ nuke. For the events, we have to remove the *.LCK file, release the
locks, flush the stream save the pointers etc ... hurry and wait...
I this point I'm pretty much ranting. */
/* You are not expected to understand this macro, but read the next page if
* you are not faint of heart.
*
* Known formats to the VALID macro are:
* From user Wed Dec 2 05:53 1992
* BSD From user Wed Dec 2 05:53:22 1992
* SysV From user Wed Dec 2 05:53 PST 1992
* rn From user Wed Dec 2 05:53:22 PST 1992
* From user Wed Dec 2 05:53 -0700 1992
* From user Wed Dec 2 05:53:22 -0700 1992
* From user Wed Dec 2 05:53 1992 PST
* From user Wed Dec 2 05:53:22 1992 PST
* From user Wed Dec 2 05:53 1992 -0700
* Solaris From user Wed Dec 2 05:53:22 1992 -0700
*
* Plus all of the above with `` remote from xxx'' after it. Thank you very
* much, smail and Solaris, for making my life considerably more complicated.
*/
/*
* What? You want to understand the VALID macro anyway? Alright, since you
* insist. Actually, it isn't really all that difficult, provided that you
* take it step by step.
*
* Line 1 Initializes the return ti value to failure (0);
* Lines 2-3 Validates that the 1st-5th characters are ``From ''.
* Lines 4-6 Validates that there is an end of line and points x at it.
* Lines 7-14 First checks to see if the line is at least 41 characters long
.
* If so, it scans backwards to find the rightmost space. From
* that point, it scans backwards to see if the string matches
* `` remote from''. If so, it sets x to point to the space at
* the start of the string.
* Line 15 Makes sure that there are at least 27 characters in the line.
* Lines 16-21 Checks if the date/time ends with the year (there is a space
* five characters back). If there is a colon three characters
* further back, there is no timezone field, so zn is set to 0
* and ti is set in front of the year. Otherwise, there must
* either to be a space four characters back for a three-letter
* timezone, or a space six characters back followed by a + or -
* for a numeric timezone; in either case, zn and ti become the
* offset of the space immediately before it.
* Lines 22-24 Are the failure case for line 14. If there is a space four
* characters back, it is a three-letter timezone; there must be
a
* space for the year nine characters back. zn is the zone
* offset; ti is the offset of the space.
* Lines 25-28 Are the failure case for line 20. If there is a space six
* characters back, it is a numeric timezone; there must be a
* space eleven characters back and a + or - five characters back
.
* zn is the zone offset; ti is the offset of the space.
* Line 29-32 If ti is valid, make sure that the string before ti is of the
* form www mmm dd hh:mm or www mmm dd hh:mm:ss, otherwise
* invalidate ti. There must be a colon three characters back
* and a space six or nine characters back (depending upon
* whether or not the character six characters back is a colon).
* There must be a space three characters further back (in front
* of the day), one seven characters back (in front of the month)
,
* and one eleven characters back (in front of the day of week).
* ti is set to be the offset of the space before the time.
*
* Why a macro? It gets invoked a *lot* in a tight loop. On some of the
* newer pipelined machines it is faster being open-coded than it would be if
* subroutines are called.
*
* Why does it scan backwards from the end of the line, instead of doing the
* much easier forward scan? There is no deterministic way to parse the
* ``user'' field, because it may contain unquoted spaces! Yes, I tested it t
o
* see if unquoted spaces were possible. They are, and I've encountered enoug
h
* evil mail to be totally unwilling to trust that ``it will never happen''.
*/
#define VALID(s,x,ti,zn) do \
{ \
ti = 0; \
if ((*s == 'F') && (s[1] == 'r') && (s[2] == 'o') && (s[3] == 'm') && \
(s[4] == ' ')) \
{ \
for (x = s + 5; *x && *x != '\n'; x++); \
if (x) \
{ \
if (x - s >= 41) \
{ \
for (zn = -1; x[zn] != ' '; zn--); \
if ((x[zn - 1] == 'm') && (x[zn - 2] == 'o') \
&& (x[zn - 3] == 'r') && (x[zn - 4] == 'f') \
&& (x[zn - 5] == ' ') && (x[zn - 6] == 'e') \
&& (x[zn - 7] == 't') && (x[zn - 8] == 'o') \
&& (x[zn - 9] == 'm') && (x[zn - 10] == 'e') \
&& (x[zn - 11] == 'r') && (x[zn - 12] == ' ')) \
x += zn - 12; \
} \
if (x - s >= 27) \
{ \
if (x[-5] == ' ') \
{ \
if (x[-8] == ':') \
zn = 0, ti = -5; \
else if (x[-9] == ' ') \
ti = zn = -9; \
else if ((x[-11] == ' ') \
&& ((x[-10] == '+') || (x[-10] == '-'))) \
ti = zn = -11; \
} \
else if (x[-4] == ' ') \
{ \
if (x[-9] == ' ') \
zn = -4, ti = -9; \
} \
else if (x[-6] == ' ') \
{ \
if ((x[-11] == ' ') && ((x[-5] == '+') || (x[-5] == '-')))\
zn = -6, ti = -11; \
} \
if (ti && !((x[ti - 3] == ':') && \
(x[ti -= ((x[ti - 6] == ':') ? 9 : 6)] == ' ') && \
(x[ti - 3] == ' ') && (x[ti - 7] == ' ') && \
(x[ti - 11] == ' '))) \
ti = 0; \
} \
} \
} \
} \
while (0)
#define ATTRIBUTE_SET(buf,mum,c0,c1,type) \
do \
{ \
char *s; \
for (s = (buf) + 7; *s; s++) \
{ \
if (*s == c0 || *s == c1) \
{ \
(mum)->attr_flags |= (type); \
break; \
} \
} \
} while (0)
/* Notifications ADD_MESG. */
#define DISPATCH_ADD_MSG(mbox,mud) \
do \
{ \
int bailing = 0; \
mu_monitor_unlock (mbox->monitor); \
if (mbox->observable) \
{ \
size_t tmp = mud->messages_count + 1; \
bailing = mu_observable_notify (mbox->observable, MU_EVT_MESSAGE_ADD, \
&tmp); \
} \
if (bailing != 0) \
{ \
mu_locker_unlock (mbox->locker); \
return EINTR; \
} \
mu_monitor_wrlock (mbox->monitor); \
} while (0);
/* Notification MBX_PROGRESS
We do not want to fire up the progress notification every line, it will be
too expensive, so we do it arbitrarely every 10 000 Lines.
FIXME: maybe this should be configurable. */
/* This is more tricky we can not leave the mum struct incomplete. So we
only tell them about the complete messages. */
#define DISPATCH_PROGRESS(mbox,mud) \
do \
{ \
int bailing = 0; \
mu_monitor_unlock (mbox->monitor); \
mud->messages_count--; \
if (mbox->observable) \
bailing = mu_observable_notify (mbox->observable, \
MU_EVT_MAILBOX_PROGRESS, NULL); \
if (bailing != 0) \
{ \
mu_locker_unlock (mbox->locker); \
return EINTR; \
} \
mud->messages_count++; \
mu_monitor_wrlock (mbox->monitor); \
} while (0)
/* Allocate slots for the new messages. */
/* size_t num = 2 * ((mud)->messages_count) + 10; */
#define ALLOCATE_MSGS(mbox,mud) \
do \
{ \
if ((mud)->messages_count >= (mud)->umessages_count) \
{ \
mbox_message_t *m; \
size_t num = ((mud)->umessages_count) + 1; \
m = realloc ((mud)->umessages, num * sizeof (*m)); \
if (m == NULL) \
{ \
mu_locker_unlock (mbox->locker); \
mu_monitor_unlock (mbox->monitor); \
return ENOMEM; \
} \
(mud)->umessages = m; \
(mud)->umessages[num - 1] = calloc (1, sizeof (*(mum))); \
if ((mud)->umessages[num - 1] == NULL) \
{ \
mu_locker_unlock (mbox->locker); \
mu_monitor_unlock (mbox->monitor); \
return ENOMEM; \
} \
(mud)->umessages_count = num; \
} \
} while (0)
#define ISSTATUS(buf) ( \
(buf[0] == 'S' || buf[0] == 's') \
&& (buf[1] == 'T' || buf[1] == 't') \
&& (buf[2] == 'A' || buf[2] == 'a') \
&& (buf[3] == 'T' || buf[3] == 't') \
&& (buf[4] == 'U' || buf[4] == 'u') \
&& (buf[5] == 'S' || buf[5] == 's') \
&& (buf[6] == ':' || buf[6] == ' ' || buf[6] == '\t'))
#define MBOX_SCAN_NOTIFY 0x1
#define MBOX_SCAN_ONEMSG 0x2
int
mbox_scan_internal (mu_mailbox_t mailbox, mbox_message_t mum,
mu_off_t total,
size_t *pmin_uid,
int flags)
{
#define MSGLINELEN 1024
char buf[MSGLINELEN];
int inheader;
int inbody;
mbox_data_t mud = mailbox->data;
int status = 0;
size_t lines;
int newline;
size_t n = 0;
mu_stream_t stream;
size_t min_uid = 0;
int zn, isfrom = 0;
char *temp;
newline = 1;
errno = lines = inheader = inbody = 0;
stream = mailbox->stream;
while ((status = mu_stream_readline (stream, buf, sizeof (buf), &n)) == 0
&& n != 0)
{
int nl;
total += n;
nl = (*buf == '\n') ? 1 : 0;
VALID (buf, temp, isfrom, zn);
if ((flags & MBOX_SCAN_ONEMSG) && mum == NULL)
{
/* In one-message mode, the positioning should be exact. */
if (!isfrom)
return EINVAL; /* FIXME: Better error code, please? */
}
/* Which part of the message are we in ? */
inheader = isfrom || ((!nl) & inheader);
inbody = !isfrom & !inheader;
if (buf[n - 1] == '\n')
lines++;
if (inheader)
{
/* New message. */
if (isfrom)
{
/* Signal the end of the body. */
if (mum && !mum->body_end)
{
mum->body_end = total - n - newline;
mum->body_lines = --lines - newline;
if (mum->uid <= min_uid)
{
mum->uid = ++min_uid;
/* Note that modification for when expunging. */
mum->attr_flags |= MU_ATTRIBUTE_MODIFIED;
}
else
min_uid = mum->uid;
if (flags & MBOX_SCAN_ONEMSG)
break;
if (flags & MBOX_SCAN_NOTIFY)
DISPATCH_ADD_MSG (mailbox, mud);
}
/* Allocate_msgs will initialize mum. */
ALLOCATE_MSGS (mailbox, mud);
mud->messages_count++;
mum = mud->umessages[mud->messages_count - 1];
mum->mud = mud;
mum->header_from = total - n;
mum->header_from_end = total;
mum->body_end = mum->body = 0;
mum->attr_flags = 0;
lines = 0;
}
else if (ISSTATUS(buf))
{
ATTRIBUTE_SET(buf, mum, 'r', 'R', MU_ATTRIBUTE_READ);
ATTRIBUTE_SET(buf, mum, 'o', 'O', MU_ATTRIBUTE_SEEN);
ATTRIBUTE_SET(buf, mum, 'a', 'A', MU_ATTRIBUTE_ANSWERED);
ATTRIBUTE_SET(buf, mum, 'd', 'D', MU_ATTRIBUTE_DELETED);
}
}
/* Body. */
if (inbody)
{
/* Set the body position. */
if (mum && !mum->body)
{
mum->body = total - n + nl;
mum->header_lines = lines;
lines = 0;
}
}
newline = (inbody && lines) ? nl : 0;
/* Every 100 mesgs update the lock, it should be every minute. */
if ((mud->messages_count % 100) == 0)
mu_locker_touchlock (mailbox->locker);
/* Ping them every 1000 lines. Should be tunable. */
if (flags & MBOX_SCAN_NOTIFY)
if (((lines + 1) % 1000) == 0)
DISPATCH_PROGRESS (mailbox, mud);
} /* while */
if (mum)
{
mum->body_end = total - newline;
mum->body_lines = lines - newline;
if (mum->uid <= min_uid)
{
mum->uid = ++min_uid;
/* Note that modification for when expunging. */
mum->attr_flags |= MU_ATTRIBUTE_MODIFIED;
}
else
min_uid = mum->uid;
if (flags & MBOX_SCAN_NOTIFY)
DISPATCH_ADD_MSG (mailbox, mud);
}
if (pmin_uid)
*pmin_uid = min_uid;
return status;
}
int
mbox_scan0 (mu_mailbox_t mailbox, size_t msgno, size_t *pcount, int do_notif)
{
int status;
mbox_data_t mud = mailbox->data;
mbox_message_t mum = NULL;
mu_off_t total = 0;
size_t min_uid;
/* Sanity. */
if (mud == NULL)
return EINVAL;
/* Grab the lock. */
mu_monitor_wrlock (mailbox->monitor);
#ifdef WITH_PTHREAD
/* read() is cancellation point since we're doing a potentially
long operation. Lets make sure we clean the state. */
pthread_cleanup_push (mbox_cleanup, (void *)mailbox);
#endif
/* Save the timestamp and size. */
status = mu_stream_size (mailbox->stream, &mud->size);
if (status != 0)
{
mu_monitor_unlock (mailbox->monitor);
return status;
}
if ((status = mu_locker_lock (mailbox->locker)))
{
mu_monitor_unlock (mailbox->monitor);
return status;
}
/* Seek to the starting point. */
if (mud->umessages && msgno > 0 && mud->messages_count > 0
&& msgno <= mud->messages_count)
{
mum = mud->umessages[msgno - 1];
if (mum)
total = mum->header_from;
mud->messages_count = msgno - 1;
}
else
mud->messages_count = 0;
status = mbox_scan_internal (mailbox, mum, total, &min_uid,
do_notif ? MBOX_SCAN_NOTIFY : 0);
if (pcount)
*pcount = mud->messages_count;
mu_locker_unlock (mailbox->locker);
mu_monitor_unlock (mailbox->monitor);
/* Reset the uidvalidity. */
if (mud->messages_count > 0)
{
mum = mud->umessages[0];
if (mud->uidvalidity == 0)
{
mud->uidvalidity = (unsigned long)time (NULL);
mud->uidnext = mud->messages_count + 1;
/* Tell that we have been modified for expunging. */
mum->attr_flags |= MU_ATTRIBUTE_MODIFIED;
}
}
if (mud->messages_count > 0 && min_uid >= mud->uidnext)
{
mum = mud->umessages[0];
mud->uidnext = min_uid + 1;
mum->attr_flags |= MU_ATTRIBUTE_MODIFIED;
}
#ifdef WITH_PTHREAD
pthread_cleanup_pop (0);
#endif
return status;
}
int
mbox_scan1 (mu_mailbox_t mailbox, mu_off_t offset, int do_notif)
{
int status;
mbox_data_t mud = mailbox->data;
if (mud == NULL)
return EINVAL;
/* Grab the lock. */
mu_monitor_wrlock (mailbox->monitor);
#ifdef WITH_PTHREAD
/* read() is cancellation point since we're doing a potentially
long operation. Lets make sure we clean the state. */
pthread_cleanup_push (mbox_cleanup, (void *)mailbox);
#endif
if ((status = mu_locker_lock (mailbox->locker)))
{
mu_monitor_unlock (mailbox->monitor);
return status;
}
status = mu_stream_seek (mailbox->stream, offset, SEEK_SET, NULL);
if (status)
{
mu_monitor_unlock (mailbox->monitor);
mu_locker_unlock (mailbox->locker);
return status;
}
status = mbox_scan_internal (mailbox, NULL, offset, NULL,
MBOX_SCAN_ONEMSG |
(do_notif ? MBOX_SCAN_NOTIFY : 0));
mu_locker_unlock (mailbox->locker);
mu_monitor_unlock (mailbox->monitor);
#ifdef WITH_PTHREAD
pthread_cleanup_pop (0);
#endif
return status;
}