lib: basic message-property API

Initially, support get, set and removal of single key/value pair, as
well as removing all properties.

lib/Makefile.local

@@ -49,6 +49,7 @@ libnotmuch_cxx_srcs =		\
 	$(dir)/directory.cc	\
 	$(dir)/index.cc		\
 	$(dir)/message.cc	\
+	$(dir)/message-property.cc \
 	$(dir)/query.cc		\
 	$(dir)/query-fp.cc      \
 	$(dir)/config.cc	\

lib/message-private.h

@@ -0,0 +1,16 @@
+#ifndef MESSAGE_PRIVATE_H
+#define MESSAGE_PRIVATE_H
+
+notmuch_string_map_t *
+_notmuch_message_property_map (notmuch_message_t *message);
+
+notmuch_bool_t
+_notmuch_message_frozen (notmuch_message_t *message);
+
+void
+_notmuch_message_remove_terms (notmuch_message_t *message, const char *prefix);
+
+void
+_notmuch_message_invalidate_metadata (notmuch_message_t *message,  const char *prefix_name);
+
+#endif

lib/message-property.cc

@@ -0,0 +1,108 @@
+/* message-property.cc - Properties are like tags, but (key,value) pairs.
+ * keys are allowed to repeat.
+ *
+ * This file is part of notmuch.
+ *
+ * Copyright © 2016 David Bremner
+ *
+ * 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: David Bremner <david@tethera.net>
+ */
+
+#include "notmuch-private.h"
+#include "database-private.h"
+#include "message-private.h"
+
+notmuch_status_t
+notmuch_message_get_property (notmuch_message_t *message, const char *key, const char **value)
+{
+    if (! value)
+	return NOTMUCH_STATUS_NULL_POINTER;
+
+    *value = _notmuch_string_map_get (_notmuch_message_property_map (message), key);
+
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
+static notmuch_status_t
+_notmuch_message_modify_property (notmuch_message_t *message, const char *key, const char *value,
+				  notmuch_bool_t delete_it)
+{
+    notmuch_private_status_t private_status;
+    notmuch_status_t status;
+    char *term = NULL;
+
+    status = _notmuch_database_ensure_writable (_notmuch_message_database (message));
+    if (status)
+	return status;
+
+    if (key == NULL || value == NULL)
+	return NOTMUCH_STATUS_NULL_POINTER;
+
+    if (index (key, '='))
+	return NOTMUCH_STATUS_ILLEGAL_ARGUMENT;
+
+    term = talloc_asprintf (message, "%s=%s", key, value);
+
+    if (delete_it)
+	private_status = _notmuch_message_remove_term (message, "property", term);
+    else
+	private_status = _notmuch_message_add_term (message, "property", term);
+
+    if (private_status)
+	return COERCE_STATUS (private_status,
+			      "Unhandled error modifying message property");
+    if (! _notmuch_message_frozen (message))
+	_notmuch_message_sync (message);
+
+    if (term)
+	talloc_free (term);
+
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
+notmuch_status_t
+notmuch_message_add_property (notmuch_message_t *message, const char *key, const char *value)
+{
+    return _notmuch_message_modify_property (message, key, value, FALSE);
+}
+
+notmuch_status_t
+notmuch_message_remove_property (notmuch_message_t *message, const char *key, const char *value)
+{
+    return _notmuch_message_modify_property (message, key, value, TRUE);
+}
+
+notmuch_status_t
+notmuch_message_remove_all_properties (notmuch_message_t *message, const char *key)
+{
+    notmuch_status_t status;
+    const char * term_prefix;
+
+    status = _notmuch_database_ensure_writable (_notmuch_message_database (message));
+    if (status)
+	return status;
+
+    _notmuch_message_invalidate_metadata (message, "property");
+    if (key)
+	term_prefix = talloc_asprintf (message, "%s%s=", _find_prefix ("property"), key);
+    else
+	term_prefix = _find_prefix ("property");
+
+    /* XXX better error reporting ? */
+    _notmuch_message_remove_terms (message, term_prefix);
+
+    return NOTMUCH_STATUS_SUCCESS;
+}

lib/message.cc

@@ -20,6 +20,7 @@
 
 #include "notmuch-private.h"
 #include "database-private.h"
+#include "message-private.h"
 
 #include <stdint.h>
 
@@ -395,7 +396,7 @@ _notmuch_message_ensure_metadata (notmuch_message_t *message)
 	message->in_reply_to = talloc_strdup (message, "");
 }
 
-static void
+void
 _notmuch_message_invalidate_metadata (notmuch_message_t *message,
 				      const char *prefix_name)
 {
@@ -552,7 +553,7 @@ notmuch_message_get_replies (notmuch_message_t *message)
     return _notmuch_messages_create (message->replies);
 }
 
-static void
+void
 _notmuch_message_remove_terms (notmuch_message_t *message, const char *prefix)
 {
     Xapian::TermIterator i;
@@ -1799,3 +1800,50 @@ _notmuch_message_database (notmuch_message_t *message)
 {
     return message->notmuch;
 }
+
+void
+_notmuch_message_ensure_property_map (notmuch_message_t *message)
+{
+    notmuch_string_node_t *node;
+
+    if (message->property_map)
+	return;
+
+    if (!message->property_term_list)
+	_notmuch_message_ensure_metadata (message);
+
+    message->property_map = _notmuch_string_map_create (message);
+
+    for (node = message->property_term_list->head; node; node = node->next) {
+	const char *key;
+	char *value;
+
+	value = index(node->string, '=');
+	if (!value)
+	    INTERNAL_ERROR ("malformed property term");
+
+	*value = '\0';
+	value++;
+	key = node->string;
+
+	_notmuch_string_map_append (message->property_map, key, value);
+
+    }
+
+    talloc_free (message->property_term_list);
+    message->property_term_list = NULL;
+}
+
+notmuch_string_map_t *
+_notmuch_message_property_map (notmuch_message_t *message)
+{
+    _notmuch_message_ensure_property_map (message);
+
+    return message->property_map;
+}
+
+notmuch_bool_t
+_notmuch_message_frozen (notmuch_message_t *message)
+{
+    return message->frozen;
+}

lib/notmuch.h

@@ -179,6 +179,11 @@ typedef enum _notmuch_status {
      * passed to a function expecting an absolute path.
      */
     NOTMUCH_STATUS_PATH_ERROR,
+    /**
+     * One of the arguments violates the preconditions for the
+     * function, in a way not covered by a more specific argument.
+     */
+    NOTMUCH_STATUS_ILLEGAL_ARGUMENT,
     /**
      * Not an actual status value. Just a way to find out how many
      * valid status values there are.
@@ -1653,6 +1658,73 @@ notmuch_message_thaw (notmuch_message_t *message);
 void
 notmuch_message_destroy (notmuch_message_t *message);
 
+/**
+ * @name Message Properties
+ *
+ * This interface provides the ability to attach arbitrary (key,value)
+ * string pairs to a message, to remove such pairs, and to iterate
+ * over them.  The caller should take some care as to what keys they
+ * add or delete values for, as other subsystems or extensions may
+ * depend on these properties.
+ *
+ */
+/**@{*/
+/**
+ * Retrieve the value for a single property key
+ *
+ * *value* is set to a string owned by the message or NULL if there is
+ * no such key. In the case of multiple values for the given key, the
+ * first one is retrieved.
+ *
+ * @returns
+ * - NOTMUCH_STATUS_NULL_POINTER: *value* may not be NULL.
+ * - NOTMUCH_STATUS_SUCCESS: No error occured.
+
+ */
+notmuch_status_t
+notmuch_message_get_property (notmuch_message_t *message, const char *key, const char **value);
+
+/**
+ * Add a (key,value) pair to a message
+ *
+ * @returns
+ * - NOTMUCH_STATUS_ILLEGAL_ARGUMENT: *key* may not contain an '=' character.
+ * - NOTMUCH_STATUS_NULL_POINTER: Neither *key* nor *value* may be NULL.
+ * - NOTMUCH_STATUS_SUCCESS: No error occured.
+ */
+notmuch_status_t
+notmuch_message_add_property (notmuch_message_t *message, const char *key, const char *value);
+
+/**
+ * Remove a (key,value) pair from a message.
+ *
+ * It is not an error to remove a non-existant (key,value) pair
+ *
+ * @returns
+ * - NOTMUCH_STATUS_ILLEGAL_ARGUMENT: *key* may not contain an '=' character.
+ * - NOTMUCH_STATUS_NULL_POINTER: Neither *key* nor *value* may be NULL.
+ * - NOTMUCH_STATUS_SUCCESS: No error occured.
+ */
+notmuch_status_t
+notmuch_message_remove_property (notmuch_message_t *message, const char *key, const char *value);
+
+/**
+ * Remove all (key,value) pairs from the given message.
+ *
+ * @param[in,out] message  message to operate on.
+ * @param[in]     key      key to delete properties for. If NULL, delete
+ *			   properties for all keys
+ * @returns
+ * - NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in
+ *   read-only mode so message cannot be modified.
+ * - NOTMUCH_STATUS_SUCCESS: No error occured.
+ *
+ */
+notmuch_status_t
+notmuch_message_remove_all_properties (notmuch_message_t *message, const char *key);
+
+/**@}*/
+
 /**
  * Is the given 'tags' iterator pointing at a valid tag.
  *

test/T610-message-property.sh

@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+test_description="message property API"
+
+. ./test-lib.sh || exit 1
+
+add_email_corpus
+
+cat <<EOF > c_head
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <notmuch-test.h>
+
+int main (int argc, char** argv)
+{
+   notmuch_database_t *db;
+   notmuch_message_t *message = NULL;
+   const char *val;
+   notmuch_status_t stat;
+
+   EXPECT0(notmuch_database_open (argv[1], NOTMUCH_DATABASE_MODE_READ_WRITE, &db));
+   EXPECT0(notmuch_database_find_message(db, "4EFC743A.3060609@april.org", &message));
+   if (message == NULL) {
+	fprintf (stderr, "unable to find message");
+	exit (1);
+   }
+EOF
+
+cat <<EOF > c_tail
+   EXPECT0(notmuch_database_destroy(db));
+}
+EOF
+
+test_begin_subtest "notmuch_message_{add,get,remove}_property"
+cat c_head - c_tail <<'EOF' | test_C ${MAIL_DIR}
+{
+   EXPECT0(notmuch_message_add_property (message, "testkey1", "testvalue1"));
+   EXPECT0(notmuch_message_get_property (message, "testkey1", &val));
+   printf("testkey1[1] = %s\n", val);
+   EXPECT0(notmuch_message_add_property (message, "testkey2", "this value has spaces and = sign"));
+   EXPECT0(notmuch_message_get_property (message, "testkey1", &val));
+   printf("testkey1[2] = %s\n", val);
+   EXPECT0(notmuch_message_get_property (message, "testkey1", &val));
+
+   EXPECT0(notmuch_message_get_property (message, "testkey2", &val));
+   printf("testkey2 = %s\n", val);
+
+   /* Add second value for key */
+   EXPECT0(notmuch_message_add_property (message, "testkey2", "zztestvalue3"));
+   EXPECT0(notmuch_message_get_property (message, "testkey2", &val));
+   printf("testkey2 = %s\n", val);
+
+   /* remove first value for key */
+   EXPECT0(notmuch_message_remove_property (message, "testkey2", "this value has spaces and = sign"));
+   EXPECT0(notmuch_message_get_property (message, "testkey2", &val));
+   printf("testkey2 = %s\n", val);
+
+   /* remove non-existant value for key */
+   EXPECT0(notmuch_message_remove_property (message, "testkey2", "this value has spaces and = sign"));
+   EXPECT0(notmuch_message_get_property (message, "testkey2", &val));
+   printf("testkey2 = %s\n", val);
+
+   /* remove only value for key */
+   EXPECT0(notmuch_message_remove_property (message, "testkey2", "zztestvalue3"));
+   EXPECT0(notmuch_message_get_property (message, "testkey2", &val));
+   printf("testkey2 = %s\n", val == NULL ? "NULL" : val);
+}
+EOF
+cat <<'EOF' >EXPECTED
+== stdout ==
+testkey1[1] = testvalue1
+testkey1[2] = testvalue1
+testkey2 = this value has spaces and = sign
+testkey2 = this value has spaces and = sign
+testkey2 = zztestvalue3
+testkey2 = zztestvalue3
+testkey2 = NULL
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+
+
+test_done