merge

dbms/src/Storages/Page/V3/BlobStore.cpp

@@ -1038,7 +1038,7 @@ std::vector<BlobFileId> BlobStore::getGCStats()
             if (right_margin != stat->sm_total_size)
             {
                 auto blobfile = getBlobFile(stat->id);
-                LOG_FMT_INFO(log, "Truncate blob file [blob_id={}] [origin size={}] [truncated size={}]", stat->id, stat->sm_total_size, right_margin);
+                LOG_FMT_TRACE(log, "Truncate blob file [blob_id={}] [origin size={}] [truncated size={}]", stat->id, stat->sm_total_size, right_margin);
                 blobfile->truncate(right_margin);
                 blobstore_gc_info.appendToTruncatedBlob(stat->id, stat->sm_total_size, right_margin, stat->sm_valid_rate);
 

dbms/src/Storages/Page/V3/spacemap/SpaceMap.h

@@ -95,9 +95,9 @@ class SpaceMap
     virtual std::tuple<UInt64, UInt64, bool> searchInsertOffset(size_t size) = 0;
 
     /**
-     * Get the used boundary of current SpaceMap. 
-     * If last node is [xxx, end]. Then `[margin_offset, +∞)` is not used at all. Return the `start` of last node.
-     * If last node is not [xxx, end]. Then right margin must be `end`.
+     * Get the used boundary of this SpaceMap. 
+     * The return value (`used_boundary`) means that `[used_bounary + 1, +∞)` is safe to be truncated.
+     * If the `used_boundary` is equal to the `end` of this SpaceMap, it means that there is no space to be truncated.
      */
     virtual UInt64 getUsedBoundary() = 0;
 

dbms/src/Storages/Page/V3/spacemap/SpaceMapRBTree.cpp

@@ -744,15 +744,13 @@ UInt64 RBTreeSpaceMap::getUsedBoundary()
 
     auto * entry = node_to_entry(node);
 
-    // If last node is not [xxx, end]
-    // Then we should return `end` rather than last node start
+    // If the `offset+size` of the last free node is not equal to `end`, it means the range `[last_node.offset, end)` is marked as used,
+    // then we should return `end` as the used boundary.
     //
-    // When there is a space with a span of [xxx, end],
-    // Then `getUsedBoundary` will return an incorrect right margin.
-    // ex.
-    //  1. Space limit is 100. So current space is [0, 100]
-    //  2. Mark a span {offset=90, size=10} as used, then the free range in SpaceMap is [0, 90).
-    //  3. without this check, `getUsedBoundary` will return 0. This is incorrect.
+    // eg.
+    //  1. The spacemap manage a space of `[0, 100]`
+    //  2. A span {offset=90, size=10} is marked as used, then the free range in SpaceMap is `[0, 90)`
+    //  3. The return value should be 100
     if (entry->start + entry->count != end)
     {
         return end;

dbms/src/Storages/Page/V3/spacemap/SpaceMapSTDMap.h

@@ -120,15 +120,13 @@ class STDMapSpaceMap
 
         const auto & last_node_it = free_map.rbegin();
 
-        // If last node is not [xxx, end]
-        // Then we should return `end` rather than last node start
+        // If the `offset+size` of the last free node is not equal to `end`, it means the range `[last_node.offset, end)` is marked as used,
+        // then we should return `end` as the used boundary.
         //
-        // When there is a space with a span of [xxx, end],
-        // Then `getUsedBoundary` will return an incorrect right margin.
-        // ex.
-        //  1. Space limit is 100. So current space is [0, 100]
-        //  2. Mark a span {offset=90, size=10} as used, then the free range in SpaceMap is [0, 90).
-        //  3. without this check, `getUsedBoundary` will return 0. This is incorrect.
+        // eg.
+        //  1. The spacemap manage a space of `[0, 100]`
+        //  2. A span {offset=90, size=10} is marked as used, then the free range in SpaceMap is `[0, 90)`
+        //  3. The return value should be 100
         if (last_node_it->first + last_node_it->second != end)
         {
             return end;