notmuch/notmuch-private.h

/* notmuch-private.h - Internal interfaces for notmuch.
 *
 * Copyright © 2009 Carl Worth
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/ .
 *
 * Author: Carl Worth <cworth@cworth.org>
 */

#ifndef NOTMUCH_PRIVATE_H
#define NOTMUCH_PRIVATE_H

#include "notmuch.h"

NOTMUCH_BEGIN_DECLS

#ifndef _GNU_SOURCE
#define _GNU_SOURCE /* For getline */
#endif

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>

#include <talloc.h>

#include "xutil.h"

/* Thanks to Andrew Tridgell's (SAMBA's) talloc for this definition of
 * unlikely. The talloc source code comes to us via the GNU LGPL v. 3.
 */
/* these macros gain us a few percent of speed on gcc */
#if (__GNUC__ >= 3)
/* the strange !! is to ensure that __builtin_expect() takes either 0 or 1
   as its first argument */
#ifndef likely
#define likely(x)   __builtin_expect(!!(x), 1)
#endif
#ifndef unlikely
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif
#else
#ifndef likely
#define likely(x) (x)
#endif
#ifndef unlikely
#define unlikely(x) (x)
#endif
#endif

/* These value numbers are chosen to be sup compatible (for now at
 * least). */

typedef enum {
    NOTMUCH_VALUE_MESSAGE_ID = 0,
    NOTMUCH_VALUE_THREAD = 1,
    NOTMUCH_VALUE_DATE = 2
} notmuch_value_t;

/* Xapian (with flint backend) complains if we provide a term longer
 * than this, but I haven't yet found a way to query the limit
 * programmatically. */
#define NOTMUCH_TERM_MAX 245

typedef enum _notmuch_private_status {
    /* First, copy all the public status values. */
    NOTMUCH_PRIVATE_STATUS_SUCCESS = NOTMUCH_STATUS_SUCCESS,
    NOTMUCH_PRIVATE_STATUS_XAPIAN_EXCEPTION = NOTMUCH_STATUS_XAPIAN_EXCEPTION,
    NOTMUCH_PRIVATE_STATUS_FILE_NOT_EMAIL = NOTMUCH_STATUS_FILE_NOT_EMAIL,
    NOTMUCH_PRIVATE_STATUS_NULL_POINTER = NOTMUCH_STATUS_NULL_POINTER,
    NOTMUCH_PRIVATE_STATUS_TAG_TOO_LONG = NOTMUCH_STATUS_TAG_TOO_LONG,

    /* Then add our own private values. */
    NOTMUCH_PRIVATE_STATUS_TERM_TOO_LONG,

    NOTMUCH_PRIVATE_STATUS_LAST_STATUS
} notmuch_private_status_t;

/* message.cc */

notmuch_message_t *
_notmuch_message_create (const void *talloc_owner,
			 notmuch_database_t *notmuch,
			 unsigned int doc_id);

/* XXX: Here temporarily during code movement only. */
/* "128 bits of thread-id ought to be enough for anybody" */
#define NOTMUCH_THREAD_ID_BITS	 128
#define NOTMUCH_THREAD_ID_DIGITS (NOTMUCH_THREAD_ID_BITS / 4)
typedef struct _thread_id {
    char str[NOTMUCH_THREAD_ID_DIGITS + 1];
} thread_id_t;


void
thread_id_generate (thread_id_t *thread_id);

/* Lookup a prefix value by name.
 *
 * XXX: This should really be static inside of message.cc, and we can
 * do that once we convert database.cc to use the
 * _notmuch_message_add/remove_term functions. */
const char *
_find_prefix (const char *name);

notmuch_private_status_t
_notmuch_message_add_term (notmuch_message_t *message,
			   const char *prefix_name,
			   const char *value);

notmuch_private_status_t
_notmuch_message_remove_term (notmuch_message_t *message,
			      const char *prefix_name,
			      const char *value);

/* message-file.c */

/* XXX: I haven't decided yet whether these will actually get exported
 * into the public interface in notmuch.h
 */

typedef struct _notmuch_message_file notmuch_message_file_t;

/* Open a file containing a single email message.
 *
 * The caller should call notmuch_message_close when done with this.
 *
 * Returns NULL if any error occurs.
 */
notmuch_message_file_t *
notmuch_message_file_open (const char *filename);

/* Close a notmuch message preivously opened with notmuch_message_open. */
void
notmuch_message_file_close (notmuch_message_file_t *message);

/* Restrict 'message' to only save the named headers.
 *
 * When the caller is only interested in a short list of headers,
 * known in advance, calling this function can avoid wasted time and
 * memory parsing/saving header values that will never be needed.
 *
 * The variable arguments should be a list of const char * with a
 * final '(const char *) NULL' to terminate the list.
 *
 * If this function is called, it must be called before any calls to
 * notmuch_message_get_header for this message.
 *
 * After calling this function, if notmuch_message_get_header is
 * called with a header name not in this list, then NULL will be
 * returned even if that header exists in the actual message.
 */
void
notmuch_message_file_restrict_headers (notmuch_message_file_t *message, ...);

/* Identical to notmuch_message_restrict_headers but accepting a va_list. */
void
notmuch_message_file_restrict_headersv (notmuch_message_file_t *message,
					va_list va_headers);

/* Get the value of the specified header from the message.
 *
 * The header name is case insensitive.
 *
 * The returned value is owned by the notmuch message and is valid
 * only until the message is closed. The caller should copy it if
 * needing to modify the value or to hold onto it for longer.
 *
 * Returns NULL if the message does not contain a header line matching
 * 'header'.
 */
const char *
notmuch_message_file_get_header (notmuch_message_file_t *message,
				 const char *header);

/* date.c */

/* Parse an RFC 8222 date string to a time_t value.
 *
 * The tz_offset argument can be used to also obtain the time-zone
 * offset, (but can be NULL if the call is not interested in that).
 *
 * Returns 0 on error.
 */
time_t
notmuch_parse_date (const char *str, int *tz_offset);

/* sha1.c */

/* Create a hexadecimal string version of the SHA-1 digest of the
 * named file.
 *
 * This function returns a newly allocated string which the caller
 * should free() when finished.
 *
 * If any error occurs while reading the file, (permission denied,
 * file not found, etc.), this function returns NULL.
 */
char *
notmuch_sha1_of_file (const char *filename);

NOTMUCH_END_DECLS

#endif