notmuch/notmuch.h
Carl Worth c12823648e Add public notmuch_thread_get_subject
And use this in "notmuch search" to display subject line as well as
thread ID.
2009-10-26 17:35:31 -07:00

720 lines
24 KiB
C

/* notmuch - Not much of an email library, (just index and search)
*
* 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_H
#define NOTMUCH_H
#ifdef __cplusplus
# define NOTMUCH_BEGIN_DECLS extern "C" {
# define NOTMUCH_END_DECLS }
#else
# define NOTMUCH_BEGIN_DECLS
# define NOTMUCH_END_DECLS
#endif
NOTMUCH_BEGIN_DECLS
#include <time.h>
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
typedef int notmuch_bool_t;
/* Status codes used for the return values of most functions.
*
* A zero value (NOTMUCH_STATUS_SUCCESS) indicates that the function
* completed without error. Any other value indicates an error as
* follows:
*
* NOTMUCH_STATUS_SUCCESS: No error occurred.
*
* NOTMUCH_STATUS_OUT_OF_MEMORY: Out of memory
*
* XXX: We don't really want to expose this lame XAPIAN_EXCEPTION
* value. Instead we should map to things like DATABASE_LOCKED or
* whatever.
*
* NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred
*
* NOTMUCH_STATUS_FILE_ERROR: An error occurred trying to read or
* write to a file (this could be file not found, permission
* denied, etc.)
*
* NOTMUCH_STATUS_FILE_NOT_EMAIL: A file was presented that doesn't
* appear to be an email message.
*
* NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: A file contains a message ID
* that is identical to a message already in the database.
*
* NOTMUCH_STATUS_NULL_POINTER: The user erroneously passed a NULL
* pointer to a notmuch function.
*
* NOTMUCH_STATUS_TAG_TOO_LONG: A tag value is too long (exceeds
* NOTMUCH_TAG_MAX)
*
* NOTMUCH_STATUS_LAST_STATUS: Not an actual status value. Just a way
* to find out how many valid status values there are.
*/
typedef enum _notmuch_status {
NOTMUCH_STATUS_SUCCESS = 0,
NOTMUCH_STATUS_OUT_OF_MEMORY,
NOTMUCH_STATUS_XAPIAN_EXCEPTION,
NOTMUCH_STATUS_FILE_ERROR,
NOTMUCH_STATUS_FILE_NOT_EMAIL,
NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID,
NOTMUCH_STATUS_NULL_POINTER,
NOTMUCH_STATUS_TAG_TOO_LONG,
NOTMUCH_STATUS_LAST_STATUS
} notmuch_status_t;
/* Get a string representation of a notmuch_status_t value.
*
* The result is readonly.
*/
const char *
notmuch_status_to_string (notmuch_status_t status);
/* Various opaque data types. For each notmuch_<foo>_t see the various
* notmuch_<foo> functions below. */
typedef struct _notmuch_database notmuch_database_t;
typedef struct _notmuch_query notmuch_query_t;
typedef struct _notmuch_thread_results notmuch_thread_results_t;
typedef struct _notmuch_thread notmuch_thread_t;
typedef struct _notmuch_message_results notmuch_message_results_t;
typedef struct _notmuch_message notmuch_message_t;
typedef struct _notmuch_tags notmuch_tags_t;
/* Lookup the default database path.
*
* This is the path that will be used by notmuch_database_create and
* notmuch_database_open if given a NULL path. Specifically it will be
* the value of the NOTMUCH_BASE environment variable if set,
* otherwise ${HOME}/mail
*
* Returns a newly allocated string which the caller should free()
* when finished with it.
*/
char *
notmuch_database_default_path (void);
/* Create a new, empty notmuch database located at 'path'.
*
* The path should be a top-level directory to a collection of
* plain-text email messages (one message per file). This call will
* create a new ".notmuch" directory within 'path' where notmuch will
* store its data.
*
* Passing a value of NULL for 'path' will cause notmuch to open the
* default database. The default database path can be specified by the
* NOTMUCH_BASE environment variable, and is equivalent to
* ${HOME}/mail if NOTMUCH_BASE is not set.
*
* After a successful call to notmuch_database_create, the returned
* database will be open so the caller should call
* notmuch_database_close when finished with it.
*
* The database will not yet have any data in it
* (notmuch_database_create itself is a very cheap function). Messages
* contained within 'path' can be added to the database by calling
* notmuch_database_add_message.
*
* In case of any failure, this function returns NULL, (after printing
* an error message on stderr).
*/
notmuch_database_t *
notmuch_database_create (const char *path);
/* XXX: I think I'd like this to take an extra argument of
* notmuch_status_t* for returning a status value on failure. */
/* Open a an existing notmuch database located at 'path'.
*
* The database should have been created at some time in the past,
* (not necessarily by this process), by calling
* notmuch_database_create with 'path'.
*
* An existing notmuch database can be identified by the presence of a
* directory named ".notmuch" below 'path'.
*
* Passing a value of NULL for 'path' will cause notmuch to open the
* default database. The default database path can be specified by the
* NOTMUCH_BASE environment variable, and is equivalent to
* ${HOME}/mail if NOTMUCH_BASE is not set.
*
* The caller should call notmuch_database_close when finished with
* this database.
*
* In case of any failure, this function returns NULL, (after printing
* an error message on stderr).
*/
notmuch_database_t *
notmuch_database_open (const char *path);
/* Close the given notmuch database, freeing all associated
* resources. See notmuch_database_open. */
void
notmuch_database_close (notmuch_database_t *database);
/* Return the database path of the given database.
*
* The return value is a string owned by notmuch so should not be
* modified nor freed by the caller. */
const char *
notmuch_database_get_path (notmuch_database_t *database);
/* Store a timestamp within the database.
*
* The Notmuch database will not interpret this key nor the timestamp
* values at all. It will merely store them together and return the
* timestamp when notmuch_database_get_timestamp is called with the
* same value for 'key'.
*
* The intention is for the caller to use the timestamp to allow
* efficient identification of new messages to be added to the
* database. The recommended usage is as follows:
*
* o Read the mtime of a directory from the filesystem
*
* o Call add_message for all mail files in the directory
*
* o Call notmuch_database_set_timestamp with the path of the
* directory as 'key' and the originally read mtime as 'value'.
*
* Then, when wanting to check for updates to the directory in the
* future, the client can call notmuch_database_get_timestamp and know
* that it only needs to add files if the mtime of the directory and
* files are newer than the stored timestamp.
*
* Note: The notmuch_database_get_timestamp function does not allow
* the caller to distinguish a timestamp of 0 from a non-existent
* timestamp. So don't store a timestamp of 0 unless you are
* comfortable with that.
*
* Return value:
*
* NOTMUCH_STATUS_SUCCESS: Timestamp successfully stored in database.
*
* NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception
* occurred. Timestamp not stored.
*/
notmuch_status_t
notmuch_database_set_timestamp (notmuch_database_t *database,
const char *key, time_t timestamp);
/* Retrieve a timestamp from the database.
*
* Returns the timestamp value previously stored by calling
* notmuch_database_set_timestamp with the same value for 'key'.
*
* Returns 0 if no timestamp is stored for 'key' or if any error
* occurred querying the database.
*/
time_t
notmuch_database_get_timestamp (notmuch_database_t *database,
const char *key);
/* Add a new message to the given notmuch database.
*
* Here,'filename' should be a path relative to the the path of
* 'database' (see notmuch_database_get_path). The file should be a
* single mail message (not a multi-message mbox) that is expected to
* remain at its current location, (since the notmuch database will
* reference the filename, and will not copy the entire contents of
* the file.
*
* Return value:
*
* NOTMUCH_STATUS_SUCCESS: Message successfully added to database.
*
* NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID: Message has the same message
* ID as another message already in the database. Nothing added
* to the database.
*
* NOTMUCH_STATUS_FILE_ERROR: an error occurred trying to open the
* file, (such as permission denied, or file not found,
* etc.). Nothing added to the database.
*
* NOTMUCH_STATUS_FILE_NOT_EMAIL: the contents of filename don't look
* like an email message. Nothing added to the database.
*/
notmuch_status_t
notmuch_database_add_message (notmuch_database_t *database,
const char *filename);
/* Find a message with the given messsage_id.
*
* If the database contains a message with the given message_id, then
* a new notmuch_message_t object is returned. The caller should call
* notmuch_message_destroy when done with the message.
*
* If no message is found with the given message_id or if an
* out-of-memory situation occurs, this function returns NULL.
*/
notmuch_message_t *
notmuch_database_find_message (notmuch_database_t *database,
const char *message_id);
/* Create a new query for 'database'.
*
* Here, 'database' should be an open database, (see
* notmuch_database_open and notmuch_database_create).
*
* For the query string, we'll document the syntax here more
* completely in the future, but it's likely to be a specialized
* version of the general Xapian query syntax:
*
* http://xapian.org/docs/queryparser.html
*
* As a special case, passing a length-zero string, (that is ""), will
* result in a query that returns all messages in the database.
*
* See notmuch_query_set_sort for controlling the order of results and
* notmuch_query_search to actually execute the query.
*
* User should call notmuch_query_destroy when finished with this
* query.
*
* Will return NULL if insufficient memory is available.
*/
notmuch_query_t *
notmuch_query_create (notmuch_database_t *database,
const char *query_string);
/* Sort values for notmuch_query_set_sort */
typedef enum {
NOTMUCH_SORT_DATE_OLDEST_FIRST,
NOTMUCH_SORT_DATE_NEWEST_FIRST,
NOTMUCH_SORT_MESSAGE_ID
} notmuch_sort_t;
/* Specify the sorting desired for this query. */
void
notmuch_query_set_sort (notmuch_query_t *query, notmuch_sort_t sort);
/* Execute a query for threads, returning a notmuch_thread_results_t
* object which can be used to iterate over the results. The results
* object is owned by the query and as such, will only be valid until
* notmuch_query_destroy.
*
* Typical usage might be:
*
* notmuch_query_t *query;
* notmuch_thread_results_t *results;
* notmuch_thread_t *thread;
*
* query = notmuch_query_create (database, query_string);
*
* for (results = notmuch_query_search_threads (query);
* notmuch_thread_results_has_more (results);
* notmuch_thread_results_advance (results))
* {
* thread = notmuch_thread_results_get (results);
* ....
* notmuch_thread_destroy (thread);
* }
*
* notmuch_query_destroy (query);
*
* Note: If you are finished with a thread before its containing
* query, you can call notmuch_thread_destroy to clean up some memory
* sooner (as in the above example). Otherwise, if your thread objects
* are long-lived, then you don't need to call notmuch_thread_destroy
* and all the memory will still be reclaimed when the query is
* destroyed.
*
* Note that there's no explicit destructor needed for the
* notmuch_thread_results_t object. (For consistency, we do provide a
* notmuch_thread_results_destroy function, but there's no good reason
* to call it if the query is about to be destroyed).
*/
notmuch_thread_results_t *
notmuch_query_search_threads (notmuch_query_t *query);
/* Execute a query for messages, returning a notmuch_message_results_t
* object which can be used to iterate over the results. The results
* object is owned by the query and as such, will only be valid until
* notmuch_query_destroy.
*
* Typical usage might be:
*
* notmuch_query_t *query;
* notmuch_message_results_t *results;
* notmuch_message_t *message;
*
* query = notmuch_query_create (database, query_string);
*
* for (results = notmuch_query_search_messages (query);
* notmuch_message_results_has_more (results);
* notmuch_message_results_advance (results))
* {
* message = notmuch_message_results_get (results);
* ....
* notmuch_message_destroy (message);
* }
*
* notmuch_query_destroy (query);
*
* Note: If you are finished with a message before its containing
* query, you can call notmuch_message_destroy to clean up some memory
* sooner (as in the above example). Otherwise, if your message
* objects are long-lived, then you don't need to call
* notmuch_message_destroy and all the memory will still be reclaimed
* when the query is destroyed.
*
* Note that there's no explicit destructor needed for the
* notmuch_message_results_t object. (For consistency, we do provide a
* notmuch_message_results_destroy function, but there's no good
* reason to call it if the query is about to be destroyed).
*/
notmuch_message_results_t *
notmuch_query_search_messages (notmuch_query_t *query);
/* Destroy a notmuch_query_t along with any associated resources.
*
* This will in turn destroy any notmuch_thread_results_t and
* notmuch_message_results_t objects generated by this query, (and in
* turn any notmuch_thrad_t and notmuch_message_t objects generated
* from those results, etc.), if such objects haven't already been
* destroyed.
*/
void
notmuch_query_destroy (notmuch_query_t *query);
/* Does the given notmuch_thread_results_t object contain any more
* results.
*
* When this function returns TRUE, notmuch_thread_results_get will
* return a valid object. Whereas when this function returns FALSE,
* notmuch_thread_results_get will return NULL.
*
* See the documentation of notmuch_query_search_threads for example
* code showing how to iterate over a notmuch_thread_results_t object.
*/
notmuch_bool_t
notmuch_thread_results_has_more (notmuch_thread_results_t *results);
/* Get the current result from 'results' as a notmuch_thread_t.
*
* Note: The returned thread belongs to 'results' and has a lifetime
* identical to it (and the query to which it belongs).
*
* See the documentation of notmuch_query_search_threads for example
* code showing how to iterate over a notmuch_thread_results_t object.
*
* If an out-of-memory situation occurs, this function will return
* NULL.
*/
notmuch_thread_t *
notmuch_thread_results_get (notmuch_thread_results_t *results);
/* Advance the 'results' iterator to the next result.
*
* See the documentation of notmuch_query_search_threads for example
* code showing how to iterate over a notmuch_thread_results_t object.
*/
void
notmuch_thread_results_advance (notmuch_thread_results_t *results);
/* Destroy a notmuch_thread_results_t object.
*
* It's not strictly necessary to call this function. All memory from
* the notmuch_thread_results_t object will be reclaimed when the
* containg query object is destroyed.
*/
void
notmuch_thread_results_destroy (notmuch_thread_results_t *results);
/* Get the thread ID of 'thread'.
*
* The returned string belongs to 'thread' and as such, should not be
* modified by the caller and will only be valid for as long as the
* thread is valid, (which is until notmuch_thread_destroy or until
* the query from which it derived is destroyed).
*/
const char *
notmuch_thread_get_thread_id (notmuch_thread_t *thread);
/* Get the subject of 'thread'
*
* The subject is taken from the first message (according to the query
* order---see notmuch_query_set_sort) in the query results that
* belongs to this thread.
*
* The returned string belongs to 'thread' and as such, should not be
* modified by the caller and will only be valid for as long as the
* thread is valid, (which is until notmuch_thread_destroy or until
* the query from which it derived is destroyed).
*/
const char *
notmuch_thread_get_subject (notmuch_thread_t *thread);
/* Get the tags for 'thread', returning a notmuch_tags_t object which
* can be used to iterate over all tags.
*
* Note: In the Notmuch database, tags are stored on individual
* messages, not on threads. So the tags returned here will be all
* tags of the messages which matched the search and which belong to
* this thread.
*
* The tags object is owned by the thread and as such, will only be
* valid for as long as the thread is valid, (for example, until
* notmuch_thread_destroy or until the query from which it derived is
* destroyed).
*
* Typical usage might be:
*
* notmuch_thread_t *thread;
* notmuch_tags_t *tags;
* const char *tag;
*
* thread = notmuch_thread_results_get (thread_results);
*
* for (tags = notmuch_thread_get_tags (thread);
* notmuch_tags_has_more (tags);
* notmuch_result_advance (tags))
* {
* tag = notmuch_tags_get (tags);
* ....
* }
*
* notmuch_thread_destroy (thread);
*
* Note that there's no explicit destructor needed for the
* notmuch_tags_t object. (For consistency, we do provide a
* notmuch_tags_destroy function, but there's no good reason to call
* it if the message is about to be destroyed).
*/
notmuch_tags_t *
notmuch_thread_get_tags (notmuch_thread_t *thread);
/* Destroy a notmuch_thread_t object. */
void
notmuch_thread_destroy (notmuch_thread_t *thread);
/* Does the given notmuch_message_results_t object contain any more
* results.
*
* When this function returns TRUE, notmuch_message_results_get will
* return a valid object. Whereas when this function returns FALSE,
* notmuch_message_results_get will return NULL.
*
* See the documentation of notmuch_query_search_messages for example
* code showing how to iterate over a notmuch_message_results_t
* object.
*/
notmuch_bool_t
notmuch_message_results_has_more (notmuch_message_results_t *results);
/* Get the current result from 'results' as a notmuch_message_t.
*
* Note: The returned message belongs to 'results' and has a lifetime
* identical to it (and the query to which it belongs).
*
* See the documentation of notmuch_query_search_messages for example
* code showing how to iterate over a notmuch_message_results_t
* object.
*
* If an out-of-memory situation occurs, this function will return
* NULL.
*/
notmuch_message_t *
notmuch_message_results_get (notmuch_message_results_t *results);
/* Advance the 'results' iterator to the next result.
*
* See the documentation of notmuch_query_search_messages for example
* code showing how to iterate over a notmuch_message_results_t
* object.
*/
void
notmuch_message_results_advance (notmuch_message_results_t *results);
/* Destroy a notmuch_message_results_t object.
*
* It's not strictly necessary to call this function. All memory from
* the notmuch_message_results_t object will be reclaimed when the
* containg query object is destroyed.
*/
void
notmuch_message_results_destroy (notmuch_message_results_t *results);
/* Get the message ID of 'message'.
*
* The returned string belongs to 'message' and as such, should not be
* modified by the caller and will only be valid for as long as the
* message is valid, (which is until the query from which it derived
* is destroyed).
*
* This function will not return NULL since Notmuch ensures that every
* message has a unique message ID, (Notmuch will generate an ID for a
* message if the original file does not contain one).
*/
const char *
notmuch_message_get_message_id (notmuch_message_t *message);
/* Get the thread ID of 'message'.
*
* The returned string belongs to 'message' and as such, should not be
* modified by the caller and will only be valid for as long as the
* message is valid, (for example, until the user calls
* notmuch_message_destroy on 'message' or until a query from which it
* derived is destroyed).
*
* This function will not return NULL since Notmuch ensures that every
* message belongs to a single thread.
*/
const char *
notmuch_message_get_thread_id (notmuch_message_t *message);
/* Get the filename for the email corresponding to 'message'.
*
* The returned filename is relative to the base of the database from
* which 'message' was obtained. See notmuch_database_get_path() .
* The returned string belongs to the message so should not be
* modified or freed by the caller (nor should it be referenced after
* the message is destroyed). */
const char *
notmuch_message_get_filename (notmuch_message_t *message);
/* Get the tags for 'message', returning a notmuch_tags_t object which
* can be used to iterate over all tags.
*
* The tags object is owned by the message and as such, will only be
* valid for as long as the message is valid, (which is until the
* query from which it derived is destroyed).
*
* Typical usage might be:
*
* notmuch_message_t *message;
* notmuch_tags_t *tags;
* const char *tag;
*
* message = notmuch_database_find_message (database, message_id);
*
* for (tags = notmuch_message_get_tags (message);
* notmuch_tags_has_more (tags);
* notmuch_result_advance (tags))
* {
* tag = notmuch_tags_get (tags);
* ....
* }
*
* notmuch_message_destroy (message);
*
* Note that there's no explicit destructor needed for the
* notmuch_tags_t object. (For consistency, we do provide a
* notmuch_tags_destroy function, but there's no good reason to call
* it if the message is about to be destroyed).
*/
notmuch_tags_t *
notmuch_message_get_tags (notmuch_message_t *message);
/* The longest possible tag value. */
#define NOTMUCH_TAG_MAX 200
/* Add a tag to the given message.
*
* Return value:
*
* NOTMUCH_STATUS_SUCCESS: Tag successfully added to message
*
* NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
*
* NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is longer than
* too long (exceeds NOTMUCH_TAG_MAX)
*/
notmuch_status_t
notmuch_message_add_tag (notmuch_message_t *message, const char *tag);
/* Remove a tag from the given message.
*
* Return value:
*
* NOTMUCH_STATUS_SUCCESS: Tag successfully added to message
*
* NOTMUCH_STATUS_NULL_POINTER: The 'tag' argument is NULL
*
* NOTMUCH_STATUS_TAG_TOO_LONG: The length of 'tag' is longer than
* too long (exceeds NOTMUCH_TAG_MAX)
*/
notmuch_status_t
notmuch_message_remove_tag (notmuch_message_t *message, const char *tag);
/* Destroy a notmuch_message_t object.
*
* It can be useful to call this function in the case of a single
* query object with many messages in the result, (such as iterating
* over the entire database). Otherwise, it's fine to never call this
* function and there will still be no memory leaks. (The memory from
* the messages get reclaimed when the containing query is destroyed.)
*/
void
notmuch_message_destroy (notmuch_message_t *message);
/* Does the given notmuch_tags_t object contain any more tags.
*
* When this function returns TRUE, notmuch_tags_get will return a
* valid string. Whereas when this function returns FALSE,
* notmuch_tags_get will return NULL.
*
* See the documentation of notmuch_message_get_tags for example code
* showing how to iterate over a notmuch_tags_t object.
*/
notmuch_bool_t
notmuch_tags_has_more (notmuch_tags_t *tags);
/* Get the current tag from 'tags' as a string.
*
* Note: The returned string belongs to 'tags' and has a lifetime
* identical to it (and the query to which it utlimately belongs).
*
* See the documentation of notmuch_message_get_tags for example code
* showing how to iterate over a notmuch_tags_t object.
*/
const char *
notmuch_tags_get (notmuch_tags_t *tags);
/* Advance the 'tags' iterator to the next tag.
*
* See the documentation of notmuch_message_get_tags for example code
* showing how to iterate over a notmuch_tags_t object.
*/
void
notmuch_tags_advance (notmuch_tags_t *tags);
/* Destroy a notmuch_tags_t object.
*
* It's not strictly necessary to call this function. All memory from
* the notmuch_tags_t object will be reclaimed when the containg
* message or query objects are destroyed.
*/
void
notmuch_tags_destroy (notmuch_tags_t *tags);
NOTMUCH_END_DECLS
#endif