tag-util.[ch]: New files for common tagging routines

These are meant to be shared between notmuch-tag and notmuch-restore.

The bulk of the routines implement a "tag operation list" abstract
data type act as a structured representation of a set of tag
operations (typically coming from a single tag command or line of
input).

3 files changed, 441 insertions, 0 deletions

diff --git a/Makefile.local b/Makefile.local
index 0db1713e..c274f073 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -275,6 +275,7 @@ notmuch_client_srcs =		\
 	query-string.c		\
 	mime-node.c		\
 	crypto.c		\
+	tag-util.c
 
 notmuch_client_modules = $(notmuch_client_srcs:.c=.o)
 
diff --git a/tag-util.c b/tag-util.c
new file mode 100644
index 00000000..6d33ef8f
--- /dev/null
+++ b/tag-util.c
@@ -0,0 +1,305 @@
+#include <assert.h>
+#include "string-util.h"
+#include "tag-util.h"
+#include "hex-escape.h"
+
+#define TAG_OP_LIST_INITIAL_SIZE 10
+
+struct _tag_operation_t {
+    const char *tag;
+    notmuch_bool_t remove;
+};
+
+struct _tag_op_list_t {
+    tag_operation_t *ops;
+    size_t count;
+    size_t size;
+};
+
+static tag_parse_status_t
+line_error (tag_parse_status_t status,
+	    const char *line,
+	    const char *format, ...)
+{
+    va_list va_args;
+
+    va_start (va_args, format);
+
+    fprintf (stderr, status < 0 ? "Error: " : "Warning: ");
+    vfprintf (stderr, format, va_args);
+    fprintf (stderr, " [%s]\n", line);
+    return status;
+}
+
+tag_parse_status_t
+parse_tag_line (void *ctx, char *line,
+		tag_op_flag_t flags,
+		char **query_string,
+		tag_op_list_t *tag_ops)
+{
+    char *tok = line;
+    size_t tok_len = 0;
+    char *line_for_error;
+    int ret = 0;
+
+    chomp_newline (line);
+
+    line_for_error = talloc_strdup (ctx, line);
+    if (line_for_error == NULL) {
+	fprintf (stderr, "Error: out of memory\n");
+	return -1;
+    }
+
+    /* remove leading space */
+    while (*tok == ' ' || *tok == '\t')
+	tok++;
+
+    /* Skip empty and comment lines. */
+    if (*tok == '\0' || *tok == '#') {
+	ret = TAG_PARSE_SKIPPED;
+	goto DONE;
+    }
+
+    tag_op_list_reset (tag_ops);
+
+    /* Parse tags. */
+    while ((tok = strtok_len (tok + tok_len, " ", &tok_len)) != NULL) {
+	notmuch_bool_t remove;
+	char *tag;
+
+	/* Optional explicit end of tags marker. */
+	if (tok_len == 2 && strncmp (tok, "--", tok_len) == 0) {
+	    tok = strtok_len (tok + tok_len, " ", &tok_len);
+	    if (tok == NULL) {
+		ret = line_error (TAG_PARSE_INVALID, line_for_error,
+				  "no query string after --");
+		goto DONE;
+	    }
+	    break;
+	}
+
+	/* Implicit end of tags. */
+	if (*tok != '-' && *tok != '+')
+	    break;
+
+	/* If tag is terminated by NUL, there's no query string. */
+	if (*(tok + tok_len) == '\0') {
+	    ret = line_error (TAG_PARSE_INVALID, line_for_error,
+			      "no query string");
+	    goto DONE;
+	}
+
+	/* Terminate, and start next token after terminator. */
+	*(tok + tok_len++) = '\0';
+
+	remove = (*tok == '-');
+	tag = tok + 1;
+
+	/* Maybe refuse empty tags. */
+	if (! (flags & TAG_FLAG_BE_GENEROUS) && *tag == '\0') {
+	    ret = line_error (TAG_PARSE_INVALID, line_for_error,
+			      "empty tag");
+	    goto DONE;
+	}
+
+	/* Decode tag. */
+	if (hex_decode_inplace (tag) != HEX_SUCCESS) {
+	    ret = line_error (TAG_PARSE_INVALID, line_for_error,
+			      "hex decoding of tag %s failed", tag);
+	    goto DONE;
+	}
+
+	if (tag_op_list_append (ctx, tag_ops, tag, remove)) {
+	    ret = line_error (TAG_PARSE_OUT_OF_MEMORY, line_for_error,
+			      "aborting");
+	    goto DONE;
+	}
+    }
+
+    if (tok == NULL) {
+	/* use a different error message for testing */
+	ret = line_error (TAG_PARSE_INVALID, line_for_error,
+			  "missing query string");
+	goto DONE;
+    }
+
+    /* tok now points to the query string */
+    if (hex_decode_inplace (tok) != HEX_SUCCESS) {
+	ret = line_error (TAG_PARSE_INVALID, line_for_error,
+			  "hex decoding of query %s failed", tok);
+	goto DONE;
+    }
+
+    *query_string = tok;
+
+  DONE:
+    talloc_free (line_for_error);
+    return ret;
+}
+
+static inline void
+message_error (notmuch_message_t *message,
+	       notmuch_status_t status,
+	       const char *format, ...)
+{
+    va_list va_args;
+
+    va_start (va_args, format);
+
+    vfprintf (stderr, format, va_args);
+    fprintf (stderr, "Message-ID: %s\n", notmuch_message_get_message_id (message));
+    fprintf (stderr, "Status: %s\n", notmuch_status_to_string (status));
+}
+
+notmuch_status_t
+tag_op_list_apply (notmuch_message_t *message,
+		   tag_op_list_t *list,
+		   tag_op_flag_t flags)
+{
+    size_t i;
+    notmuch_status_t status = 0;
+    tag_operation_t *tag_ops = list->ops;
+
+    status = notmuch_message_freeze (message);
+    if (status) {
+	message_error (message, status, "freezing message");
+	return status;
+    }
+
+    if (flags & TAG_FLAG_REMOVE_ALL) {
+	status = notmuch_message_remove_all_tags (message);
+	if (status) {
+	    message_error (message, status, "removing all tags");
+	    return status;
+	}
+    }
+
+    for (i = 0; i < list->count; i++) {
+	if (tag_ops[i].remove) {
+	    status = notmuch_message_remove_tag (message, tag_ops[i].tag);
+	    if (status) {
+		message_error (message, status, "removing tag %s", tag_ops[i].tag);
+		return status;
+	    }
+	} else {
+	    status = notmuch_message_add_tag (message, tag_ops[i].tag);
+	    if (status) {
+		message_error (message, status, "adding tag %s", tag_ops[i].tag);
+		return status;
+	    }
+
+	}
+    }
+
+    status = notmuch_message_thaw (message);
+    if (status) {
+	message_error (message, status, "thawing message");
+	return status;
+    }
+
+
+    if (flags & TAG_FLAG_MAILDIR_SYNC) {
+	status = notmuch_message_tags_to_maildir_flags (message);
+	if (status) {
+	    message_error (message, status, "synching tags to maildir");
+	    return status;
+	}
+    }
+
+    return NOTMUCH_STATUS_SUCCESS;
+
+}
+
+
+/* Array of tagging operations (add or remove.  Size will be increased
+ * as necessary. */
+
+tag_op_list_t *
+tag_op_list_create (void *ctx)
+{
+    tag_op_list_t *list;
+
+    list = talloc (ctx, tag_op_list_t);
+    if (list == NULL)
+	return NULL;
+
+    list->size = TAG_OP_LIST_INITIAL_SIZE;
+    list->count = 0;
+
+    list->ops = talloc_array (ctx, tag_operation_t, list->size);
+    if (list->ops == NULL)
+	return NULL;
+
+    return list;
+}
+
+
+int
+tag_op_list_append (void *ctx,
+		    tag_op_list_t *list,
+		    const char *tag,
+		    notmuch_bool_t remove)
+{
+    /* Make room if current array is full.  This should be a fairly
+     * rare case, considering the initial array size.
+     */
+
+    if (list->count == list->size) {
+	list->size *= 2;
+	list->ops = talloc_realloc (ctx, list->ops, tag_operation_t,
+				    list->size);
+	if (list->ops == NULL) {
+	    fprintf (stderr, "Out of memory.\n");
+	    return 1;
+	}
+    }
+
+    /* add the new operation */
+
+    list->ops[list->count].tag = tag;
+    list->ops[list->count].remove = remove;
+    list->count++;
+    return 0;
+}
+
+/*
+ *   Is the i'th tag operation a remove?
+ */
+
+notmuch_bool_t
+tag_op_list_isremove (const tag_op_list_t *list, size_t i)
+{
+    assert (i < list->count);
+    return list->ops[i].remove;
+}
+
+/*
+ * Reset a list to contain no operations
+ */
+
+void
+tag_op_list_reset (tag_op_list_t *list)
+{
+    list->count = 0;
+}
+
+/*
+ * Return the number of operations in a list
+ */
+
+size_t
+tag_op_list_size (const tag_op_list_t *list)
+{
+    return list->count;
+}
+
+/*
+ *   return the i'th tag in the list
+ */
+
+const char *
+tag_op_list_tag (const tag_op_list_t *list, size_t i)
+{
+    assert (i < list->count);
+    return list->ops[i].tag;
+}
diff --git a/tag-util.h b/tag-util.h
new file mode 100644
index 00000000..99b0fa0b
--- /dev/null
+++ b/tag-util.h
@@ -0,0 +1,135 @@
+#ifndef _TAG_UTIL_H
+#define _TAG_UTIL_H
+
+#include "notmuch-client.h"
+
+typedef struct _tag_operation_t tag_operation_t;
+typedef struct _tag_op_list_t tag_op_list_t;
+
+/* Use powers of 2 */
+typedef enum {
+    TAG_FLAG_NONE = 0,
+
+    /* Operations are synced to maildir, if possible.
+     */
+    TAG_FLAG_MAILDIR_SYNC = (1 << 0),
+
+    /* Remove all tags from message before applying list.
+     */
+    TAG_FLAG_REMOVE_ALL = (1 << 1),
+
+    /* Don't try to avoid database operations. Useful when we
+     * know that message passed needs these operations.
+     */
+    TAG_FLAG_PRE_OPTIMIZED = (1 << 2),
+
+    /* Accept strange tags that might be user error;
+     * intended for use by notmuch-restore.
+     */
+    TAG_FLAG_BE_GENEROUS = (1 << 3)
+
+} tag_op_flag_t;
+
+/* These should obey the convention that fatal errors are negative,
+ * skipped lines are positive.
+ */
+typedef enum {
+    TAG_PARSE_OUT_OF_MEMORY = -1,
+
+    /* Line parsed successfuly. */
+    TAG_PARSE_SUCCESS = 0,
+
+    /* Line has a syntax error */
+    TAG_PARSE_INVALID = 1,
+
+    /* Line was blank or a comment */
+    TAG_PARSE_SKIPPED = 2
+
+} tag_parse_status_t;
+
+/* Parse a string of the following format:
+ *
+ * +<tag>|-<tag> [...] [--] <search-terms>
+ *
+ * Each line is interpreted similarly to "notmuch tag" command line
+ * arguments. The delimiter is one or more spaces ' '. Any characters
+ * in <tag> and <search-terms> MAY be hex encoded with %NN where NN is
+ * the hexadecimal value of the character. Any ' ' and '%' characters
+ * in <tag> and <search-terms> MUST be hex encoded (using %20 and %25,
+ * respectively). Any characters that are not part of <tag> or
+ * <search-terms> MUST NOT be hex encoded.
+ *
+ * Leading and trailing space ' ' is ignored. Empty lines and lines
+ * beginning with '#' are ignored.
+ *
+ *
+ * Output Parameters:
+ *	ops	contains a list of tag operations
+ *	query_str the search terms.
+ */
+tag_parse_status_t
+parse_tag_line (void *ctx, char *line,
+		tag_op_flag_t flags,
+		char **query_str, tag_op_list_t *ops);
+
+/*
+ * Create an empty list of tag operations
+ *
+ * ctx is passed to talloc
+ */
+
+tag_op_list_t *
+tag_op_list_create (void *ctx);
+
+/*
+ * Add a tag operation (delete iff remove == TRUE) to a list.
+ * The list is expanded as necessary.
+ */
+
+int
+tag_op_list_append (void *ctx,
+		    tag_op_list_t *list,
+		    const char *tag,
+		    notmuch_bool_t remove);
+
+/*
+ * Apply a list of tag operations, in order, to a given message.
+ *
+ * Flags can be bitwise ORed; see enum above for possibilies.
+ */
+
+notmuch_status_t
+tag_op_list_apply (notmuch_message_t *message,
+		   tag_op_list_t *tag_ops,
+		   tag_op_flag_t flags);
+
+/*
+ * Return the number of operations in a list
+ */
+
+size_t
+tag_op_list_size (const tag_op_list_t *list);
+
+/*
+ * Reset a list to contain no operations
+ */
+
+void
+tag_op_list_reset (tag_op_list_t *list);
+
+
+/*
+ *   return the i'th tag in the list
+ */
+
+const char *
+tag_op_list_tag (const tag_op_list_t *list, size_t i);
+
+/*
+ *   Is the i'th tag operation a remove?
+ */
+
+notmuch_bool_t
+tag_op_list_isremove (const tag_op_list_t *list, size_t i);
+
+#endif