From f782ebd939e2d81808ad63da0a6ff36e88938da2 Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Thu, 10 Mar 2011 11:36:44 -0800
Subject: [PATCH] Add runtime options to disable some of the log-structured
 optimizations

---
 bluesky/bluesky.h  | 12 ++++++++++--
 bluesky/cloudlog.c |  5 ++++-
 bluesky/init.c     |  2 ++
 bluesky/log.c      |  3 ++-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h
index 5ef2f28..874027f 100644
--- a/bluesky/bluesky.h
+++ b/bluesky/bluesky.h
@@ -20,10 +20,10 @@ extern "C" {
 
 /* Various options to tweak for performance benchmarking purposes. */
 typedef struct {
-    /* Perform all get/put operations synchronously. */
+    /* OBSOLETE: Perform all get/put operations synchronously. */
     int synchronous_stores;
 
-    /* Write data in cache immediately after file is modified. */
+    /* OBSOLETE: Write data in cache immediately after file is modified. */
     int writethrough_cache;
 
     /* Can inodes be fetched asynchronously?  (Inode object is initially
@@ -37,6 +37,14 @@ typedef struct {
 
     /* Target size of the disk cache at the proxy, in kilobytes. */
     int cache_size;
+
+    /* Full segment fetches (1) or use range requests (0) for fetching segments
+     * from cloud? */
+    int full_segment_fetches;
+
+    /* Disable aggregating of data into log segments.  Each object will be
+     * stored in a separate segment. */
+    int disable_aggregation;
 } BlueSkyOptions;
 
 extern BlueSkyOptions bluesky_options;
diff --git a/bluesky/cloudlog.c b/bluesky/cloudlog.c
index 4b49397..3e30f02 100644
--- a/bluesky/cloudlog.c
+++ b/bluesky/cloudlog.c
@@ -449,8 +449,11 @@ BlueSkyCloudPointer bluesky_cloudlog_serialize(BlueSkyCloudLog *log,
     bluesky_cloudlog_ref(log);
     g_mutex_unlock(log->lock);
 
-    if (state->data->len > CLOUDLOG_SEGMENT_SIZE)
+    if (state->data->len > CLOUDLOG_SEGMENT_SIZE
+        || bluesky_options.disable_aggregation)
+    {
         bluesky_cloudlog_flush(fs);
+    }
 
     return log->location;
 }
diff --git a/bluesky/init.c b/bluesky/init.c
index e2b35c6..49ede3e 100644
--- a/bluesky/init.c
+++ b/bluesky/init.c
@@ -50,6 +50,8 @@ static struct {
     {"BLUESKY_OPT_SYNC_INODE_FETCH", &bluesky_options.sync_inode_fetches},
     {"BLUESKY_OPT_SYNC_FRONTENDS", &bluesky_options.sync_frontends},
     {"BLUESKY_CACHE_SIZE", &bluesky_options.cache_size},
+    {"BLUESKY_OPT_FULL_SEGMENTS", &bluesky_options.full_segment_fetches},
+    {"BLUESKY_OPT_NO_AGGREGATION", &bluesky_options.disable_aggregation},
     {NULL, NULL}
 };
 
diff --git a/bluesky/log.c b/bluesky/log.c
index 984cf16..6ac7508 100644
--- a/bluesky/log.c
+++ b/bluesky/log.c
@@ -651,7 +651,8 @@ BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data)
     BlueSkyRCStr *str = NULL;
     int location = 0;
     size_t file_offset = 0, file_size = 0;
-    gboolean range_request = TRUE;
+    gboolean range_request = bluesky_options.full_segment_fetches
+                              ? FALSE : TRUE;
 
     if (page_size == 0) {
         page_size = getpagesize();
-- 
2.20.1