feat: add InvertedIndexMetas (#121)

* feat: add `InvertedIndexFooter`

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* feat: map instead of list

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* fix: add rust mod

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* chore: rename InvertedIndexFooter to InvertedIndexMetas

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* chore: add java outer classname option

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

---------

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

build.rs

@@ -43,6 +43,7 @@ fn main() {
                 "proto/greptime/v1/meta/lock.proto",
                 "proto/greptime/v1/meta/cluster.proto",
                 "proto/greptime/v1/region/server.proto",
+                "proto/greptime/v1/index/inverted_index.proto",
                 "proto/prometheus/remote/remote.proto",
                 "proto/substrait_extension/promql_plan.proto",
             ],

c++/greptime/v1/index/inverted_index.grpc.pb.cc

@@ -0,0 +1,29 @@
+// Generated by the gRPC C++ plugin.
+// If you make any local change, they will be lost.
+// source: greptime/v1/index/inverted_index.proto
+
+#include "greptime/v1/index/inverted_index.pb.h"
+#include "greptime/v1/index/inverted_index.grpc.pb.h"
+
+#include <functional>
+#include <grpcpp/support/async_stream.h>
+#include <grpcpp/support/async_unary_call.h>
+#include <grpcpp/impl/channel_interface.h>
+#include <grpcpp/impl/client_unary_call.h>
+#include <grpcpp/support/client_callback.h>
+#include <grpcpp/support/message_allocator.h>
+#include <grpcpp/support/method_handler.h>
+#include <grpcpp/impl/rpc_service_method.h>
+#include <grpcpp/support/server_callback.h>
+#include <grpcpp/impl/codegen/server_callback_handlers.h>
+#include <grpcpp/server_context.h>
+#include <grpcpp/impl/service_type.h>
+#include <grpcpp/support/sync_stream.h>
+namespace greptime {
+namespace v1 {
+namespace index {
+
+}  // namespace greptime
+}  // namespace v1
+}  // namespace index
+

c++/greptime/v1/index/inverted_index.grpc.pb.h

@@ -0,0 +1,52 @@
+// Generated by the gRPC C++ plugin.
+// If you make any local change, they will be lost.
+// source: greptime/v1/index/inverted_index.proto
+// Original file comments:
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+#ifndef GRPC_greptime_2fv1_2findex_2finverted_5findex_2eproto__INCLUDED
+#define GRPC_greptime_2fv1_2findex_2finverted_5findex_2eproto__INCLUDED
+
+#include "greptime/v1/index/inverted_index.pb.h"
+
+#include <functional>
+#include <grpcpp/generic/async_generic_service.h>
+#include <grpcpp/support/async_stream.h>
+#include <grpcpp/support/async_unary_call.h>
+#include <grpcpp/support/client_callback.h>
+#include <grpcpp/client_context.h>
+#include <grpcpp/completion_queue.h>
+#include <grpcpp/support/message_allocator.h>
+#include <grpcpp/support/method_handler.h>
+#include <grpcpp/impl/codegen/proto_utils.h>
+#include <grpcpp/impl/rpc_method.h>
+#include <grpcpp/support/server_callback.h>
+#include <grpcpp/impl/codegen/server_callback_handlers.h>
+#include <grpcpp/server_context.h>
+#include <grpcpp/impl/service_type.h>
+#include <grpcpp/impl/codegen/status.h>
+#include <grpcpp/support/stub_options.h>
+#include <grpcpp/support/sync_stream.h>
+
+namespace greptime {
+namespace v1 {
+namespace index {
+
+}  // namespace index
+}  // namespace v1
+}  // namespace greptime
+
+
+#endif  // GRPC_greptime_2fv1_2findex_2finverted_5findex_2eproto__INCLUDED

proto/greptime/v1/index/inverted_index.proto

@@ -0,0 +1,74 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package greptime.v1.index;
+
+option java_package = "io.greptime.v1.index";
+option java_outer_classname = "Index";
+option go_package = "github.com/GreptimeTeam/greptime-proto/go/greptime/v1/index";
+
+// InvertedIndexMetas defines the metadata for an inverted index
+// within an SST file.
+message InvertedIndexMetas {
+    // A map of tag names to their respective metadata corresponding to an individual
+    // inverted index within the SST file.
+    map<string, InvertedIndexMeta> metas = 1;
+}
+
+// InvertedIndexMeta contains the metadata for a specific tag's inverted index.
+message InvertedIndexMeta {
+    // Name of the tag associated with the inverted index.
+    string name = 1;
+
+    // Defines the number of rows per group for bitmap indexing. It determines how rows
+    // are batched for indexing, with each batch corresponding to a segment in the bitmap.
+    // The groups are usually of uniform size, with the exception of the final group which
+    // may contain fewer rows if the total row count is not a multiple of 'row_count_in_group'.
+    // Segmenting allows indexed values in the tag column to be quickly located within
+    // their respective groups during a query, reducing the search space and improving
+    // retrieval efficiency.
+    uint64 row_count_in_group = 2;
+
+    // The byte offset of the Finite State Transducer (FST) within the SST file.
+    uint64 fst_offset = 3;
+
+    // The size in bytes of the FST data.
+    uint64 fst_size = 4;
+
+    // The byte offset where the null bitmap for this tag starts.
+    uint64 null_bitmap_offset = 5;
+
+    // The size in bytes of the null bitmap.
+    uint64 null_bitmap_size = 6;
+
+    // Statistical information about the tag's inverted index.
+    InvertedIndexStats stats = 7;
+}
+
+// InvertedIndexStats provides statistical data on a tag's inverted index.
+message InvertedIndexStats {
+    // The count of null entries within the tag's column.
+    uint64 null_count = 1;
+
+    // The number of distinct values within the tag's column.
+    uint64 distinct_count = 2;
+
+    // The minimum value found within the tag's column, encoded as bytes.
+    bytes min_value = 3;
+
+    // The maximum value found within the tag's column, encoded as bytes.
+    bytes max_value = 4;
+}

src/v1.rs

@@ -18,6 +18,7 @@ use crate::v1::value::ValueData;
 
 pub const GREPTIME_GRPC_DESC: &[u8] = tonic::include_file_descriptor_set!("greptime_grpc_desc");
 
+pub mod index;
 pub mod meta;
 pub mod region;
 

src/v1/index.rs

@@ -0,0 +1,15 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+tonic::include_proto!("greptime.v1.index");