[RFC PATCH 05/13] notmuch_database_add_message calculates sha1 of messages using mailstore

[Ethan Glasser-Camp <glasse@cs.rpi.edu>]

From: Ethan Glasser-Camp <ethan@betacantrips.com>

Previously, notmuch_database_add_message used the notmuch_sha1_of_file
function, which accesses a mail file directly. Create a new function
called notmuch_sha1_of_message which uses a mailstore to access the
file, and use that instead.

Also, as a drive-by cleanup, use the named constant BLOCK_SIZE instead
of the integer literal 4096.

Signed-off-by: Ethan Glasser-Camp <ethan@betacantrips.com>
---
 lib/database.cc       |    2 +-
 lib/notmuch-private.h |    3 ++
 lib/sha1.c            |   52 ++++++++++++++++++++++++++++++++++++------------
 3 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index e3c8095..ff44e76 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -1700,7 +1700,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 	if (message_id == NULL ) {
 	    /* No message-id at all, let's generate one by taking a
 	     * hash over the file's contents. */
-	    char *sha1 = notmuch_sha1_of_file (filename);
+	    char *sha1 = notmuch_sha1_of_message (notmuch->mailstore, filename);
 
 	    /* If that failed too, something is really wrong. Give up. */
 	    if (sha1 == NULL) {
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 0f01437..2589928 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -454,6 +454,9 @@ notmuch_sha1_of_string (const char *str);
 char *
 notmuch_sha1_of_file (const char *filename);
 
+char *
+notmuch_sha1_of_message (notmuch_mailstore_t *mailstore, const char *filename);
+
 /* string-list.c */
 
 typedef struct _notmuch_string_node {
diff --git a/lib/sha1.c b/lib/sha1.c
index cc48108..ea25999 100644
--- a/lib/sha1.c
+++ b/lib/sha1.c
@@ -64,19 +64,11 @@ notmuch_sha1_of_string (const char *str)
     return _hex_of_sha1_digest (digest);
 }
 
-/* Create a hexadecimal string version of the SHA-1 digest of the
- * contents 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.
+/* Internal function to feed the contents of a FILE * to the sha1 functions.
  */
-char *
-notmuch_sha1_of_file (const char *filename)
+static char *
+_notmuch_sha1_of_filep (FILE *file)
 {
-    FILE *file;
 #define BLOCK_SIZE 4096
     unsigned char block[BLOCK_SIZE];
     size_t bytes_read;
@@ -84,14 +76,13 @@ notmuch_sha1_of_file (const char *filename)
     unsigned char digest[SHA1_DIGEST_SIZE];
     char *result;
 
-    file = fopen (filename, "r");
     if (file == NULL)
 	return NULL;
 
     sha1_begin (&sha1);
 
     while (1) {
-	bytes_read = fread (block, 1, 4096, file);
+	bytes_read = fread (block, 1, BLOCK_SIZE, file);
 	if (bytes_read == 0) {
 	    if (feof (file)) {
 		break;
@@ -113,3 +104,38 @@ notmuch_sha1_of_file (const char *filename)
     return result;
 }
 
+/* Create a hexadecimal string version of the SHA-1 digest of the
+ * contents 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)
+{
+    FILE *file;
+
+    file = fopen (filename, "r");
+    return _notmuch_sha1_of_filep (file);
+}
+
+/* Create a hexadecimal string version of the SHA-1 digest of the
+ * contents of the named message, which is accessed via a mailstore.
+ *
+ * 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_message (notmuch_mailstore_t *mailstore, const char *filename)
+{
+    FILE *file;
+
+    file = notmuch_mailstore_open (mailstore, filename);
+    return _notmuch_sha1_of_filep (file);
+}
-- 
1.7.5.4