commit 8db5a72b61bd89ac7adfad4ac4db372779e64492
author David Rogers <davidrogers@google.com> Mon Feb 03 18:28:34 2020 -0800
committer CQ Bot Account <commit-bot@chromium.org> Tue Feb 04 23:19:55 2020 +0000
tree 3a245ec1b181415fcc42dbac4cdf8f830a9f5cb5
parent 6908e47768c298d0c25e4e67f4d61873ba2286a6

pw_kvs: Modify FindSectorWithSpace() for extra default options

Modify FindSectorWithSpace() with option to skip a sector
in the search as well as to bypass the free sector rule.

Change-Id: I750b91562a2d3af5d8952ece0db94c2c01659bb7

pw_kvs/key_value_store.cc

diff --git a/pw_kvs/key_value_store.cc b/pw_kvs/key_value_store.cc
index a778851..fdf5e14 100644
--- a/pw_kvs/key_value_store.cc
+++ b/pw_kvs/key_value_store.cc
@@ -468,10 +468,13 @@
   return Status::UNIMPLEMENTED;
 }
 
-// Find either an existing sector with enough space, or an empty sector.
-// Maintains the invariant that there is always at least 1 empty sector.
+// Find either an existing sector with enough space that is not the sector to
+// skip, or an empty sector. Maintains the invariant that there is always at
+// least 1 empty sector unless set to bypass the rule.
 KeyValueStore::SectorDescriptor* KeyValueStore::FindSectorWithSpace(
-    size_t size) {
+    size_t size,
+    SectorDescriptor* sector_to_skip,
+    bool bypass_empty_sector_rule) {
   const size_t sector_count = partition_.sector_count();
 
   // TODO: Ignore last written sector for now and scan from the beginning.
@@ -479,13 +482,18 @@
 
   size_t start = (last_written_sector_ + 1) % sector_count;
   SectorDescriptor* first_empty_sector = nullptr;
-  bool at_least_two_empty_sectors = false;
+  bool at_least_two_empty_sectors = bypass_empty_sector_rule;
 
   for (size_t i = start; i != last_written_sector_;
        i = (i + 1) % sector_count) {
     DBG("Examining sector %zu", i);
     SectorDescriptor& sector = sector_map_[i];
 
+    if (sector_to_skip == &sector) {
+      DBG("Skipping the skip sector");
+      continue;
+    }
+
     if (!SectorEmpty(sector) && sector.HasSpace(size)) {
       DBG("Partially occupied sector with enough space; done!");
       return &sector;

pw_kvs/public/pw_kvs/key_value_store.h

diff --git a/pw_kvs/public/pw_kvs/key_value_store.h b/pw_kvs/public/pw_kvs/key_value_store.h
index 8e9c9c6..2b17a97 100644
--- a/pw_kvs/public/pw_kvs/key_value_store.h
+++ b/pw_kvs/public/pw_kvs/key_value_store.h
@@ -265,7 +265,10 @@
 
   Status RelocateEntry(KeyDescriptor& key_descriptor);
 
-  SectorDescriptor* FindSectorWithSpace(size_t size);
+  SectorDescriptor* FindSectorWithSpace(
+      size_t size,
+      SectorDescriptor* sector_to_skip = nullptr,
+      bool bypass_empty_sector_rule = false);
 
   Status FindOrRecoverSectorWithSpace(SectorDescriptor** sector, size_t size);