fix row key not in standard format (#7901) (#7912)

close #3099, close #7762
pingcap · Aug 9, 2023 · 9393dbf · 9393dbf
1 parent f00dea7
commit 9393dbf
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Showing 2 changed files with 55 additions and 15 deletions.
diff --git a/dbms/src/Storages/DeltaMerge/RowKeyRange.h b/dbms/src/Storages/DeltaMerge/RowKeyRange.h
@@ -84,6 +84,46 @@ struct RowKeyValue
         {
             size_t cursor = 0;
             int_value = DB::DecodeInt64(cursor, *value);
+            if (unlikely(value->size() != sizeof(Int64)))
+            {
+                // For int type handle, the standard key enconding format should be t{table_id}_r{handle_value}.
+                // But TiKV may generate region range keys which are not strictly following the standard format.
+                // More concretely, the key may be t{table_id}_r{handle_value} + some other bytes.
+                // We need to adapt the key to the standard format.
+                // For example, the key may be t100_r1000 + 0x00, we need to adapt it to t100_r1001.
+                // This is ok, because
+                //  1) if the key is the start range, then [t100_r1000 + 0x00, xxx) has the same semantics with [t100_r1001, xxx)
+                //  2) if the key is the end range, then [xxx, t100_r1000 + 0x00) also has the same semantics with [xxx, t100_r1001)
+                //
+                // Note if the `int_value` is Int64::max_value,
+                // it is a value generated by tiflash itself to means +inf()(which is RowKeyValue::INT_HANDLE_MAX_KEY).
+                // So we can just ignore it.
+                if (value->size() != sizeof(UInt64) + 1 || value->back() != 0x00)
+                {
+                    LOG_WARNING(
+                        Logger::get(),
+                        "Meet rowkey {} with unexpected encoding format",
+                        Redact::keyToDebugString(value->data(), value->size()));
+                }
+                else
+                {
+                    if (int_value < std::numeric_limits<Int64>::max())
+                    {
+                        LOG_WARNING(
+                            Logger::get(),
+                            "Meet rowkey {} which has an extra zero suffix",
+                            Redact::keyToDebugString(value->data(), value->size()));
+                        int_value = int_value + 1;
+                        WriteBufferFromOwnString ss;
+                        DB::EncodeInt64(int_value, ss);
+                        value = std::make_shared<String>(ss.releaseStr());
+                    }
+                    else
+                    {
+                        // ignore RowKeyValue::INT_HANDLE_MAX_KEY
+                    }
+                }
+            }
         }
     }
 

diff --git a/dbms/src/Storages/DeltaMerge/tests/gtest_key_range.cpp b/dbms/src/Storages/DeltaMerge/tests/gtest_key_range.cpp
@@ -119,21 +119,21 @@ TEST(RowKey, ToNextKeyIntHandle)
             /* row_key_column_size */ 1);
         EXPECT_EQ(0, compare(next.toRowKeyValueRef(), range.getEnd()));
     }
-    // Note: The following does not work, because {20,00} will be regarded as Key=20 in RowKeyRange::fromRegionRange.
-    // {
-    //     auto key_end = RecordKVFormat::genRawKey(1, 20);
-    //     key_end.push_back(0);
-    //     auto tikv_key_end = RecordKVFormat::encodeAsTiKVKey(key_end);
-    //     const auto range_keys = std::make_shared<RegionRangeKeys>(
-    //         RecordKVFormat::genKey(1, 0),
-    //         std::move(tikv_key_end));
-    //     const auto range = RowKeyRange::fromRegionRange(
-    //         range_keys,
-    //         /* table_id */ 1,
-    //         /* is_common_handle */ false,
-    //         /* row_key_column_size */ 1);
-    //     EXPECT_EQ(0, compare(next.toRowKeyValueRef(), range.getEnd()));
-    // }
+    // Note: {20,00} will be regarded as Key=21 in RowKeyRange::fromRegionRange.
+    {
+        auto key_end = RecordKVFormat::genRawKey(1, 20);
+        key_end.push_back(0);
+        auto tikv_key_end = RecordKVFormat::encodeAsTiKVKey(key_end);
+        const auto range_keys = std::make_shared<RegionRangeKeys>(
+            RecordKVFormat::genKey(1, 0),
+            std::move(tikv_key_end));
+        const auto range = RowKeyRange::fromRegionRange(
+            range_keys,
+            /* table_id */ 1,
+            /* is_common_handle */ false,
+            /* row_key_column_size */ 1);
+        EXPECT_EQ(0, compare(next.toRowKeyValueRef(), range.getEnd()));
+    }
 }
 
 TEST(RowKey, ToNextKeyCommonHandle)