From 6443fe537efa35cdad192b2d35ea0398cce56c17 Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Sun, 29 Nov 2009 11:47:51 -0800
Subject: [PATCH] Some initial work to support delayed flushing of data.

---
 bluesky/bluesky.h |  6 ++++++
 bluesky/file.c    | 11 +++++++++++
 bluesky/inode.c   |  3 +++
 3 files changed, 20 insertions(+)

diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h
index 3bdfd59..7f237d3 100644
--- a/bluesky/bluesky.h
+++ b/bluesky/bluesky.h
@@ -141,6 +141,11 @@ typedef struct {
      * committed to stable storage. */
     uint64_t change_count, change_commit;
 
+    /* Timestamp for controlling when modified data is flushed to stable
+     * storage.  When an inode is first modified from a clean state, this is
+     * set to the current time.  If the inode is clean, it is set to zero. */
+    int64_t change_time;
+
     int64_t atime;              /* Microseconds since the Unix epoch */
     int64_t ctime;
     int64_t mtime;
@@ -210,6 +215,7 @@ void bluesky_directory_dump(BlueSkyInode *dir);
 void bluesky_block_touch(BlueSkyInode *inode, uint64_t i);
 void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block);
 void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block);
+void bluesky_file_flush(BlueSkyInode *inode);
 void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size);
 void bluesky_file_write(BlueSkyInode *inode, uint64_t offset,
                         const char *data, gint len);
diff --git a/bluesky/file.c b/bluesky/file.c
index f9f6444..9f4d980 100644
--- a/bluesky/file.c
+++ b/bluesky/file.c
@@ -215,3 +215,14 @@ void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block)
     g_checksum_free(csum);
     //bluesky_string_unref(data);
 }
+
+/* Flush all blocks in a file to stable storage. */
+void bluesky_file_flush(BlueSkyInode *inode)
+{
+    g_return_if_fail(inode->type == BLUESKY_REGULAR);
+
+    for (int i = 0; i < inode->blocks->len; i++) {
+        BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
+        bluesky_block_flush(inode->fs, b);
+    }
+}
diff --git a/bluesky/inode.c b/bluesky/inode.c
index e0d237b..0c745e8 100644
--- a/bluesky/inode.c
+++ b/bluesky/inode.c
@@ -37,6 +37,9 @@ void bluesky_inode_update_ctime(BlueSkyInode *inode, gboolean update_mtime)
     inode->ctime = now;
     if (update_mtime)
         inode->mtime = now;
+
+    if (inode->change_time == 0)
+        inode->change_time = now;
 }
 
 /* Unfortunately a glib hash table is only guaranteed to be able to store
-- 
2.20.1