notmuch/database.cc
Carl Worth ad784f38ce notmuch: Ignore files that don't look like email messages.
This is helpful for things like indexes that other mail programs
may have left around. It also means we can make the initial
instructions much easier, (the user need not worry about moving
away auxiliary files from some other email program).
2009-10-19 23:16:05 -07:00

595 lines
14 KiB
C++

/* database.cc - The database interfaces of the notmuch mail library
*
* 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>
*/
#include "notmuch-private.h"
#include <iostream>
#include <xapian.h>
#include <glib.h> /* g_strdup_printf, g_free, GHashTable */
using namespace std;
struct _notmuch_database {
char *path;
Xapian::WritableDatabase *xapian_db;
Xapian::TermGenerator *term_gen;
};
#define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
/* Xapian complains if we provide a term longer than this. */
#define NOTMUCH_MAX_TERM 245
/* These prefix values are specifically chosen to be compatible
* with sup, (http://sup.rubyforge.org), written by
* William Morgan <wmorgan-sup@masanjin.net>, and released
* under the GNU GPL v2.
*/
typedef struct {
const char *name;
const char *prefix;
} prefix_t;
prefix_t NORMAL_PREFIX[] = {
{ "subject", "S" },
{ "body", "B" },
{ "from_name", "FN" },
{ "to_name", "TN" },
{ "name", "N" },
{ "attachment", "A" }
};
prefix_t BOOLEAN_PREFIX[] = {
{ "type", "K" },
{ "from_email", "FE" },
{ "to_email", "TE" },
{ "email", "E" },
{ "date", "D" },
{ "label", "L" },
{ "source_id", "I" },
{ "attachment_extension", "O" },
{ "msgid", "Q" },
{ "thread", "H" },
{ "ref", "R" }
};
/* Similarly, these value numbers are also chosen to be sup
* compatible. */
typedef enum {
NOTMUCH_VALUE_MESSAGE_ID = 0,
NOTMUCH_VALUE_THREAD = 1,
NOTMUCH_VALUE_DATE = 2
} notmuch_value_t;
static const char *
find_prefix (const char *name)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE (NORMAL_PREFIX); i++)
if (strcmp (name, NORMAL_PREFIX[i].name) == 0)
return NORMAL_PREFIX[i].prefix;
for (i = 0; i < ARRAY_SIZE (BOOLEAN_PREFIX); i++)
if (strcmp (name, BOOLEAN_PREFIX[i].name) == 0)
return BOOLEAN_PREFIX[i].prefix;
return "";
}
/* "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;
static void
thread_id_generate (thread_id_t *thread_id)
{
static int seeded = 0;
FILE *dev_random;
uint32_t value;
char *s;
int i;
if (! seeded) {
dev_random = fopen ("/dev/random", "r");
if (dev_random == NULL) {
srand (time (NULL));
} else {
fread ((void *) &value, sizeof (value), 1, dev_random);
srand (value);
fclose (dev_random);
}
seeded = 1;
}
s = thread_id->str;
for (i = 0; i < NOTMUCH_THREAD_ID_DIGITS; i += 8) {
value = rand ();
sprintf (s, "%08x", value);
s += 8;
}
}
static void
add_term (Xapian::Document doc,
const char *prefix_name,
const char *value)
{
const char *prefix;
char *term;
if (value == NULL)
return;
prefix = find_prefix (prefix_name);
term = g_strdup_printf ("%s%s", prefix, value);
if (strlen (term) <= NOTMUCH_MAX_TERM)
doc.add_term (term);
g_free (term);
}
static void
find_messages_by_term (Xapian::Database *db,
const char *prefix_name,
const char *value,
Xapian::PostingIterator *begin,
Xapian::PostingIterator *end)
{
Xapian::PostingIterator i;
char *term;
term = g_strdup_printf ("%s%s", find_prefix (prefix_name), value);
*begin = db->postlist_begin (term);
if (end)
*end = db->postlist_end (term);
free (term);
}
Xapian::Document
find_message_by_docid (Xapian::Database *db, Xapian::docid docid)
{
return db->get_document (docid);
}
Xapian::Document
find_message_by_message_id (Xapian::Database *db, const char *message_id)
{
Xapian::PostingIterator i, end;
find_messages_by_term (db, "msgid", message_id, &i, &end);
if (i != end)
return find_message_by_docid (db, *i);
else
return Xapian::Document ();
}
static void
insert_thread_id (GHashTable *thread_ids, Xapian::Document doc)
{
string value_string;
const char *value, *id, *comma;
value_string = doc.get_value (NOTMUCH_VALUE_THREAD);
value = value_string.c_str();
if (strlen (value)) {
id = value;
while (*id) {
comma = strchr (id, ',');
if (comma == NULL)
comma = id + strlen (id);
g_hash_table_insert (thread_ids,
strndup (id, comma - id), NULL);
id = comma;
if (*id)
id++;
}
}
}
/* Return one or more thread_ids, (as a GPtrArray of strings), for the
* given message based on looking into the database for any messages
* referenced in parents, and also for any messages in the database
* referencing message_id.
*
* Caller should free all strings in the array and the array itself,
* (g_ptr_array_free) when done. */
static GPtrArray *
find_thread_ids (Xapian::Database *db,
GPtrArray *parents,
const char *message_id)
{
Xapian::PostingIterator child, children_end;
Xapian::Document doc;
GHashTable *thread_ids;
GList *keys, *l;
unsigned int i;
const char *parent_message_id;
GPtrArray *result;
thread_ids = g_hash_table_new_full (g_str_hash, g_str_equal,
free, NULL);
find_messages_by_term (db, "ref", message_id, &child, &children_end);
for ( ; child != children_end; child++) {
doc = find_message_by_docid (db, *child);
insert_thread_id (thread_ids, doc);
}
for (i = 0; i < parents->len; i++) {
parent_message_id = (char *) g_ptr_array_index (parents, i);
doc = find_message_by_message_id (db, parent_message_id);
insert_thread_id (thread_ids, doc);
}
result = g_ptr_array_new ();
keys = g_hash_table_get_keys (thread_ids);
for (l = keys; l; l = l->next) {
char *id = (char *) l->data;
g_ptr_array_add (result, id);
}
g_list_free (keys);
/* We're done with the hash table, but we've taken the pointers to
* the allocated strings and put them into our result array, so
* tell the hash not to free them on its way out. */
g_hash_table_steal_all (thread_ids);
g_hash_table_unref (thread_ids);
return result;
}
/* Advance 'str' past any whitespace or RFC 822 comments. A comment is
* a (potentially nested) parenthesized sequence with '\' used to
* escape any character (including parentheses).
*
* If the sequence to be skipped continues to the end of the string,
* then 'str' will be left pointing at the final terminating '\0'
* character.
*/
static void
skip_space_and_comments (const char **str)
{
const char *s;
s = *str;
while (*s && (isspace (*s) || *s == '(')) {
while (*s && isspace (*s))
s++;
if (*s == '(') {
int nesting = 1;
s++;
while (*s && nesting) {
if (*s == '(')
nesting++;
else if (*s == ')')
nesting--;
else if (*s == '\\')
if (*(s+1))
s++;
s++;
}
}
}
*str = s;
}
/* Parse an RFC 822 message-id, discarding whitespace, any RFC 822
* comments, and the '<' and '>' delimeters.
*
* If not NULL, then *next will be made to point to the first character
* not parsed, (possibly pointing to the final '\0' terminator.
*
* Returns a newly allocated string which the caller should free()
* when done with it.
*
* Returns NULL if there is any error parsing the message-id. */
static char *
parse_message_id (const char *message_id, const char **next)
{
const char *s, *end;
if (message_id == NULL)
return NULL;
s = message_id;
skip_space_and_comments (&s);
/* Skip any unstructured text as well. */
while (*s && *s != '<')
s++;
if (*s == '<') {
s++;
} else {
if (next)
*next = s;
return NULL;
}
skip_space_and_comments (&s);
end = s;
while (*end && *end != '>')
end++;
if (next) {
if (*end)
*next = end + 1;
else
*next = end;
}
if (end > s && *end == '>')
end--;
if (end > s)
return strndup (s, end - s + 1);
else
return NULL;
}
/* Parse a References header value, putting a copy of each referenced
* message-id into 'array'. */
static void
parse_references (GPtrArray *array,
const char *refs)
{
char *ref;
if (refs == NULL)
return;
while (*refs) {
ref = parse_message_id (refs, &refs);
if (ref)
g_ptr_array_add (array, ref);
}
}
notmuch_database_t *
notmuch_database_create (const char *path)
{
char *notmuch_path;
struct stat st;
int err;
err = stat (path, &st);
if (err) {
fprintf (stderr, "Error: Cannot create database at %s: %s.\n",
path, strerror (errno));
return NULL;
}
if (! S_ISDIR (st.st_mode)) {
fprintf (stderr, "Error: Cannot create database at %s: Not a directory.\n",
path);
return NULL;
}
notmuch_path = g_strdup_printf ("%s/%s", path, ".notmuch");
err = mkdir (notmuch_path, 0755);
if (err) {
fprintf (stderr, "Error: Cannot create directory %s: %s.\n",
notmuch_path, strerror (errno));
free (notmuch_path);
return NULL;
}
free (notmuch_path);
return notmuch_database_open (path);
}
notmuch_database_t *
notmuch_database_open (const char *path)
{
notmuch_database_t *notmuch;
char *notmuch_path, *xapian_path;
struct stat st;
int err;
notmuch_path = g_strdup_printf ("%s/%s", path, ".notmuch");
err = stat (notmuch_path, &st);
if (err) {
fprintf (stderr, "Error: Cannot stat %s: %s\n",
notmuch_path, strerror (err));
free (notmuch_path);
return NULL;
}
xapian_path = g_strdup_printf ("%s/%s", notmuch_path, "xapian");
free (notmuch_path);
/* C++ is so nasty in requiring these casts. I'm almost tempted to
* write a C wrapper for Xapian... */
notmuch = (notmuch_database_t *) xmalloc (sizeof (notmuch_database_t));
notmuch->path = xstrdup (path);
try {
notmuch->xapian_db = new Xapian::WritableDatabase (xapian_path,
Xapian::DB_CREATE_OR_OPEN);
} catch (const Xapian::Error &error) {
fprintf (stderr, "A Xapian exception occurred: %s\n",
error.get_msg().c_str());
}
free (xapian_path);
return notmuch;
}
void
notmuch_database_close (notmuch_database_t *notmuch)
{
delete notmuch->xapian_db;
free (notmuch->path);
free (notmuch);
}
const char *
notmuch_database_get_path (notmuch_database_t *notmuch)
{
return notmuch->path;
}
notmuch_status_t
notmuch_database_add_message (notmuch_database_t *notmuch,
const char *filename)
{
Xapian::WritableDatabase *db = notmuch->xapian_db;
Xapian::Document doc;
notmuch_message_t *message;
GPtrArray *parents, *thread_ids;
const char *refs, *in_reply_to, *date, *header;
const char *from, *to, *subject;
char *message_id;
time_t time_value;
unsigned int i;
message = notmuch_message_open (filename);
notmuch_message_restrict_headers (message,
"date",
"from",
"in-reply-to",
"message-id",
"references",
"subject",
(char *) NULL);
try {
doc = Xapian::Document ();
doc.set_data (filename);
parents = g_ptr_array_new ();
refs = notmuch_message_get_header (message, "references");
parse_references (parents, refs);
in_reply_to = notmuch_message_get_header (message, "in-reply-to");
parse_references (parents, in_reply_to);
for (i = 0; i < parents->len; i++)
add_term (doc, "ref", (char *) g_ptr_array_index (parents, i));
header = notmuch_message_get_header (message, "message-id");
if (header) {
message_id = parse_message_id (header, NULL);
/* So the header value isn't RFC-compliant, but it's
* better than no message-id at all. */
if (message_id == NULL)
message_id = xstrdup (header);
} else {
/* XXX: Should generate a message_id here, (such as a SHA1
* sum of the message itself) */
message_id = NULL;
}
thread_ids = find_thread_ids (db, parents, message_id);
for (i = 0; i < parents->len; i++)
g_free (g_ptr_array_index (parents, i));
g_ptr_array_free (parents, TRUE);
if (message_id) {
add_term (doc, "msgid", message_id);
doc.add_value (NOTMUCH_VALUE_MESSAGE_ID, message_id);
}
if (thread_ids->len) {
unsigned int i;
GString *thread_id;
char *id;
for (i = 0; i < thread_ids->len; i++) {
id = (char *) thread_ids->pdata[i];
add_term (doc, "thread", id);
if (i == 0)
thread_id = g_string_new (id);
else
g_string_append_printf (thread_id, ",%s", id);
free (id);
}
g_ptr_array_free (thread_ids, TRUE);
doc.add_value (NOTMUCH_VALUE_THREAD, thread_id->str);
g_string_free (thread_id, TRUE);
} else if (message_id) {
/* If not part of any existing thread, generate a new thread_id. */
thread_id_t thread_id;
thread_id_generate (&thread_id);
add_term (doc, "thread", thread_id.str);
doc.add_value (NOTMUCH_VALUE_THREAD, thread_id.str);
}
free (message_id);
date = notmuch_message_get_header (message, "date");
time_value = notmuch_parse_date (date, NULL);
doc.add_value (NOTMUCH_VALUE_DATE,
Xapian::sortable_serialise (time_value));
from = notmuch_message_get_header (message, "from");
subject = notmuch_message_get_header (message, "subject");
to = notmuch_message_get_header (message, "to");
if (from == NULL &&
subject == NULL &&
to == NULL)
{
notmuch_message_close (message);
return NOTMUCH_STATUS_FILE_NOT_EMAIL;
} else {
db->add_document (doc);
}
} catch (const Xapian::Error &error) {
fprintf (stderr, "A Xapian exception occurred: %s.\n",
error.get_msg().c_str());
return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
}
notmuch_message_close (message);
return NOTMUCH_STATUS_SUCCESS;
}