mbsync/debian/patches/30-async-imap.dpatch

#!/bin/sh -e
## 30-aysnc-imap.dpatch by Theodore Y. Ts'o <tytso@mit.edu>
##
## DP: Add the beginnings of asynchronous IMAP support.  So far, we only 
## DP: support asynchronous flag setting, since that's the easist.  
## DP: Eventually we need to support asynchronous message fetches and
## DP: uploads.

if [ $# -ne 1 ]; then
    echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
    exit 1
fi

[ -f debian/patches/00patch-opts ] && . debian/patches/00patch-opts
patch_opts="${patch_opts:--f --no-backup-if-mismatch}"

case "$1" in
       -patch) patch $patch_opts -p1 < $0;;
       -unpatch) patch $patch_opts -p1 -R < $0;;
        *)
                echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
                exit 1;;
esac

exit 0

@DPATCH@
diff -urNad /usr/projects/isync/SF-cvs/isync/src/imap.c isync/src/imap.c
--- /usr/projects/isync/SF-cvs/isync/src/imap.c	2004-01-14 18:31:49.000000000 -0500
+++ isync/src/imap.c	2004-01-14 18:39:18.000000000 -0500
@@ -3,6 +3,7 @@
  * isync - IMAP4 to maildir mailbox synchronizer
  * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
  * Copyright (C) 2002-2003 Oswald Buddenhagen <ossi@users.sf.net>
+ * Copyright (C) 2004 Theodore Ts'o <tytso@alum.mit.edu>
  *
  *  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
@@ -35,13 +36,33 @@
 #include <string.h>
 #include <ctype.h>
 #include <sys/socket.h>
+#include <sys/ioctl.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <arpa/inet.h>
 #include <netdb.h>
 #if HAVE_LIBSSL
 # include <openssl/err.h>
 #endif
 
+struct imap_cmd {
+	unsigned int tag;
+	char *cmd;
+	int flags;
+	int response;
+	struct imap_cmd *next;
+	int (*complete_fn) (imap_t *imap, struct imap_cmd * cmd);
+};
+
+#define IMAP_FLAG_DONE	0x0001
+
+static struct imap_cmd *in_progress = NULL;
+static int num_in_progress = 0;
+int max_in_progress_high = 50;
+int max_in_progress_low = 10;
+
+static struct imap_cmd *get_cmd_result(imap_t *imap);
+
 const char *Flags[] = {
     "\\Seen",
     "\\Answered",
@@ -199,6 +220,22 @@
     return write (sock->fd, buf, len);
 }
 
+static int
+socket_pending(Socket_t *sock)
+{
+    int num = -1;
+
+    if (ioctl(sock->fd, FIONREAD, &num) < 0)
+	    return -1;
+    if (num > 0)
+	    return num;
+#if HAVE_LIBSSL
+	if (sock->use_ssl)
+		return SSL_pending (sock->ssl);
+#endif
+	return 0;
+}
+
 static void
 socket_perror (const char *func, Socket_t *sock, int ret)
 {
@@ -301,16 +338,20 @@
 }
 
 static int
-parse_fetch (imap_t * imap, list_t * list)
+parse_fetch (imap_t * imap, char *cmd)
 {
-    list_t *tmp;
+    list_t *tmp, *list;
     unsigned int uid = 0;
     unsigned int mask = 0;
     unsigned int size = 0;
     message_t *cur;
 
-    if (!is_list (list))
+    list = parse_list (cmd, 0);
+
+    if (!is_list (list)) {
+	free_list(list);
 	return -1;
+    }
 
     for (tmp = list->child; tmp; tmp = tmp->next)
     {
@@ -325,6 +366,7 @@
 		    if (uid < imap->minuid)
 		    {
 			/* already saw this message */
+			free_list(list);
 			return 0;
 		    }
 		    else if (uid > imap->maxuid)
@@ -387,6 +429,7 @@
     cur->flags = mask;
     cur->size = size;
 
+    free_list(list);
     return 0;
 }
 
@@ -415,39 +458,114 @@
     }
 }
 
-static int
-imap_exec (imap_t * imap, const char *fmt, ...)
+static struct imap_cmd *issue_imap_cmd(imap_t *imap,
+				       const char *fmt, ...)
 {
     va_list ap;
-    char tmp[256];
-    char buf[256];
-    char *cmd;
-    char *arg;
-    char *arg1;
-    config_t *box;
+    char tmp[1024];
+    char buf[1024];
+    struct imap_cmd *cmd;
     int n;
 
+    cmd = malloc(sizeof(struct imap_cmd));
+    if (!cmd)
+	    return NULL;
+
+    cmd->tag = ++Tag;
+    cmd->flags = 0;
+    cmd->response = 0;
+    cmd->complete_fn = 0;
+
     va_start (ap, fmt);
     vsnprintf (tmp, sizeof (tmp), fmt, ap);
     va_end (ap);
 
-    snprintf (buf, sizeof (buf), "%d %s\r\n", ++Tag, tmp);
+    cmd->cmd = malloc(strlen(tmp)+1);
+    if (cmd->cmd)
+	    strcpy(cmd->cmd, tmp);
+
+    snprintf (buf, sizeof (buf), "%d %s\r\n", cmd->tag, tmp);
     if (Verbose) {
-	printf (">>> %s", buf);
+	if (num_in_progress)
+	   printf("(%d in progress) ", num_in_progress);
+	if (strncmp(tmp, "LOGIN", 5))
+	    printf (">>> %s", buf);
+	else
+	    printf (">>> LOGIN USERNAME PASSWORD\n");
 	fflush (stdout);
     }
     n = socket_write (imap->sock, buf, strlen (buf));
     if (n <= 0)
     {
 	socket_perror ("write", imap->sock, n);
-	return -1;
+	free(cmd);
+	return NULL;
+    }
+    cmd->next = in_progress;
+    in_progress = cmd;
+    num_in_progress++;
+    if ((num_in_progress > max_in_progress_high) ||
+	socket_pending(imap->sock)) {
+	    while ((num_in_progress > max_in_progress_low) ||
+		   socket_pending(imap->sock)) {
+		    if (Verbose && socket_pending(imap->sock))
+			    printf("(Socket input pending)\n");
+		    get_cmd_result(imap);
+	    }
     }
+    return cmd;
+}
+
+static struct imap_cmd *find_imap_cmd(unsigned int tag)
+{
+	struct imap_cmd *cmd, *prev;
+
+	for (prev=NULL, cmd=in_progress; cmd; cmd = cmd->next) {
+		if (tag == cmd->tag) {
+			return cmd;
+		}
+		prev = cmd;
+	}
+	return NULL;
+}
+
+static void dequeue_imap_cmd(unsigned int tag)
+{
+	struct imap_cmd *cmd, *prev;
+
+	for (prev=NULL, cmd=in_progress; cmd; cmd = cmd->next) {
+		if (tag != cmd->tag) {
+			prev = cmd;
+			continue;
+		}
+		if (prev)
+			prev->next = cmd->next;
+		else
+			in_progress = cmd->next;
+		cmd->next = 0;
+		if (cmd->cmd)
+			free(cmd->cmd);
+		cmd->cmd = 0;
+		free(cmd);
+		break;
+	}
+}
+
+static struct imap_cmd *get_cmd_result(imap_t *imap)
+{
+    char *cmd;
+    char *arg;
+    char *arg1;
+    config_t *box;
+    int n;
+    unsigned int tag;
+    struct imap_cmd *cmdp;
 
     for (;;)
     {
       next:
 	if (buffer_gets (imap->buf, &cmd))
-	    return -1;
+	    return NULL;
 
 	arg = next_arg (&cmd);
 	if (*arg == '*')
@@ -456,7 +574,7 @@
 	    if (!arg)
 	    {
 		fprintf (stderr, "IMAP error: unable to parse untagged response\n");
-		return -1;
+		return NULL;
 	    }
 
 	    if (!strcmp ("NAMESPACE", arg))
@@ -528,23 +646,14 @@
 		    imap->recent = atoi (arg);
 		else if (!strcmp ("FETCH", arg1))
 		{
-		    list_t *list;
-
-		    list = parse_list (cmd, 0);
-
-		    if (parse_fetch (imap, list))
-		    {
-			free_list (list);
-			return -1;
-		    }
-
-		    free_list (list);
+		    if (parse_fetch (imap, cmd))
+			return NULL;
 		}
 	    }
 	    else
 	    {
 		fprintf (stderr, "IMAP error: unable to parse untagged response\n");
-		return -1;
+		return NULL;
 	    }
 	}
 #if HAVE_LIBSSL
@@ -555,7 +664,7 @@
 	    if (!imap->cram)
 	    {
 		fprintf (stderr, "IMAP error, not doing CRAM-MD5 authentication\n");
-		return -1;
+		return NULL;
 	    }
 	    resp = cram (cmd, imap->box->user, imap->box->pass);
 
@@ -568,34 +677,88 @@
 	    if (n <= 0)
 	    {
 		socket_perror ("write", imap->sock, n);
-		return -1;
+		return NULL;
 	    }
 	    n = socket_write (imap->sock, "\r\n", 2);
 	    if (n <= 0)
 	    {
 		socket_perror ("write", imap->sock, n);
-		return -1;
+		return NULL;
 	    }
 	    imap->cram = 0;
 	}
 #endif
-	else if ((size_t) atol (arg) != Tag)
-	{
-	    fprintf (stderr, "IMAP error: wrong tag\n");
-	    return -1;
-	}
-	else
-	{
-	    arg = next_arg (&cmd);
-	    parse_response_code (imap, cmd);
-	    if (!strcmp ("OK", arg))
-		return 0;
-	    return -1;
+	else {
+		tag = (unsigned int) atol (arg);
+		cmdp = find_imap_cmd(tag);
+		if (!cmdp) {
+			fprintf(stderr, "IMAP error: sent unknown tag: %u\n",
+				tag);
+			return NULL;
+		}
+		arg = next_arg (&cmd);
+		if (strncmp("OK", arg, 2)) {
+			fprintf(stderr, "tag %u returned error: %s\n",
+				tag, arg);
+			cmdp->response = -1;
+		}
+		parse_response_code (imap, cmd);
+		num_in_progress--;
+		cmdp->flags |= IMAP_FLAG_DONE;
+		if (Verbose) 
+			printf("Tag %u completed with response %d\n", 
+			       cmdp->tag, cmdp->response);
+		return cmdp;
 	}
     }
     /* not reached */
 }
 
+static void flush_imap_cmds(imap_t *imap)
+{
+	struct imap_cmd *cmdp;
+
+	while (num_in_progress) {
+		if (in_progress && in_progress->flags & IMAP_FLAG_DONE) {
+			dequeue_imap_cmd(in_progress->tag);
+			continue;
+		}
+		cmdp = get_cmd_result(imap);
+		if (!cmdp)
+			printf("Error trying to flush pending imap cmds\n");
+	}
+}
+
+static int
+imap_exec (imap_t * imap, const char *fmt, ...)
+{
+    va_list ap;
+    char tmp[1024];
+    struct imap_cmd *cmdp, *waitp;
+    int result;
+
+    va_start (ap, fmt);
+    vsnprintf (tmp, sizeof (tmp), fmt, ap);
+    va_end (ap);
+
+    cmdp = issue_imap_cmd(imap, "%s", tmp);
+    if (!cmdp)
+	    return -1;
+
+    if (cmdp->flags & IMAP_FLAG_DONE)
+	    return cmdp->response;
+
+    do {
+	    waitp = get_cmd_result(imap);
+    } while (waitp->tag != cmdp->tag);
+
+    result = cmdp->response;
+    dequeue_imap_cmd(cmdp->tag);
+
+    return cmdp->response;
+
+}
+
 #ifdef HAVE_LIBSSL
 static int
 start_tls (imap_t *imap, config_t * cfg)
@@ -1039,6 +1202,7 @@
   size_t n;
   char buf[1024];
 
+  flush_imap_cmds(imap);
   send_server (imap->sock, "UID FETCH %d BODY.PEEK[]", uid);
 
   for (;;)
@@ -1160,7 +1324,9 @@
 		(buf[0] != 0) ? " " : "", Flags[i]);
   }
 
-  return imap_exec (imap, "UID STORE %d +FLAGS.SILENT (%s)", uid, buf);
+  if (issue_imap_cmd(imap, "UID STORE %d +FLAGS.SILENT (%s)", uid, buf))
+     return 0;
+  return -1;
 }
 
 int
@@ -1249,6 +1415,7 @@
     strcat (flagstr,") ");
   }
 
+  flush_imap_cmds(imap);
   send_server (imap->sock, "APPEND %s%s %s{%d}",
 	       imap->prefix, imap->box->box, flagstr, len + extra);
 
@@ -1341,6 +1508,7 @@
   }
 
   /* didn't receive an APPENDUID */
+  flush_imap_cmds(imap);
   send_server (imap->sock,
 	       "UID SEARCH HEADER X-TUID %08lx%05lx%04x", 
 	       tv.tv_sec, tv.tv_usec, pid);