From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Wed, 17 Mar 2021 15:28:03 +0000 (+0200)
Subject: imap: Add reason_code=imap:fetch_*
X-Git-Tag: 2.3.18~347
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bb1df6771968d9da0e6de4451f425714f5dfc3dc;p=thirdparty%2Fdovecot%2Fcore.git

imap: Add reason_code=imap:fetch_*

The main reason for these is to allow understanding why mails are being
opened. The possibilities:

 * imap:fetch_body
 * imap:fetch_header
 * imap:fetch_header_fields
 * imap:fetch_bodystructure
 * imap:fetch_size
---

diff --git a/src/imap/cmd-fetch.c b/src/imap/cmd-fetch.c
index d05d8d1975..35e85d15d3 100644
--- a/src/imap/cmd-fetch.c
+++ b/src/imap/cmd-fetch.c
@@ -283,6 +283,46 @@ static bool cmd_fetch_continue(struct client_command_context *cmd)
 	return cmd_fetch_finish(ctx, cmd);
 }
 
+static void cmd_fetch_set_reason_codes(struct client_command_context *cmd,
+				       struct imap_fetch_context *ctx)
+{
+	/* Fetching body or header always causes the message to be opened.
+	   Use them as the primary reason. */
+	if ((ctx->fetch_data & MAIL_FETCH_STREAM_BODY) != 0) {
+		event_strlist_append(cmd->global_event, EVENT_REASON_CODE,
+				     "imap:fetch_body");
+		return;
+	}
+	if ((ctx->fetch_data & MAIL_FETCH_STREAM_HEADER) != 0) {
+		event_strlist_append(cmd->global_event, EVENT_REASON_CODE,
+				     "imap:fetch_header");
+		return;
+	}
+
+	/* The rest of these can come from cache. Since especially with
+	   prefetching we can't really know which one of them specifically
+	   triggered opening the mail, just use all of them as the reasons. */
+	if (ctx->fetch_header_fields ||
+	    HAS_ANY_BITS(ctx->fetch_data,
+			 MAIL_FETCH_IMAP_ENVELOPE |
+			 MAIL_FETCH_DATE)) {
+		event_strlist_append(cmd->global_event, EVENT_REASON_CODE,
+				     "imap:fetch_header_fields");
+	}
+	if (HAS_ANY_BITS(ctx->fetch_data,
+			 MAIL_FETCH_IMAP_BODY |
+			 MAIL_FETCH_IMAP_BODYSTRUCTURE)) {
+		event_strlist_append(cmd->global_event, EVENT_REASON_CODE,
+				     "imap:fetch_bodystructure");
+	}
+	if (HAS_ANY_BITS(ctx->fetch_data,
+			 MAIL_FETCH_PHYSICAL_SIZE |
+			 MAIL_FETCH_VIRTUAL_SIZE)) {
+		event_strlist_append(cmd->global_event, EVENT_REASON_CODE,
+				     "imap:fetch_size");
+	}
+}
+
 bool cmd_fetch(struct client_command_context *cmd)
 {
 	struct client *client = cmd->client;
@@ -335,6 +375,7 @@ bool cmd_fetch(struct client_command_context *cmd)
 		}
 	}
 
+	cmd_fetch_set_reason_codes(cmd, ctx);
 	imap_fetch_begin(ctx, client->mailbox, search_args);
 	mail_search_args_unref(&search_args);
 
diff --git a/src/imap/imap-fetch-body.c b/src/imap/imap-fetch-body.c
index 39e66f093d..b467334ec3 100644
--- a/src/imap/imap-fetch-body.c
+++ b/src/imap/imap-fetch-body.c
@@ -251,6 +251,8 @@ body_header_fields_parse(struct imap_fetch_init_context *ctx,
 	const char *value;
 	size_t i;
 
+	ctx->fetch_ctx->fetch_header_fields = TRUE;
+
 	str = str_new(ctx->pool, 128);
 	str_append(str, prefix);
 	str_append(str, " (");
diff --git a/src/imap/imap-fetch.h b/src/imap/imap-fetch.h
index 39a0b9d4fa..ba8cfc80a9 100644
--- a/src/imap/imap-fetch.h
+++ b/src/imap/imap-fetch.h
@@ -100,6 +100,8 @@ struct imap_fetch_context {
 	bool flags_have_handler:1;
 	bool flags_update_seen:1;
 	bool flags_show_only_seen_changes:1;
+	/* HEADER.FIELDS or HEADER.FIELDS.NOT is fetched */
+	bool fetch_header_fields:1;
 };
 
 void imap_fetch_handlers_register(const struct imap_fetch_handler *handlers,