src/paimon/format/blob/blob_reader_builder.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

#pragma once

#include <map>
#include <memory>
#include <string>

#include "paimon/common/reader/blob_read_context.h"
#include "paimon/common/utils/arrow/mem_utils.h"
#include "paimon/common/utils/options_utils.h"
#include "paimon/format/blob/blob_file_batch_reader.h"
#include "paimon/format/reader_builder.h"
#include "paimon/fs/file_system.h"
#include "paimon/memory/memory_pool.h"

namespace paimon::blob {

class BlobReaderBuilder : public ReaderBuilder, public BlobReadContextAwareBuilder {
 public:
    BlobReaderBuilder(int32_t batch_size, const std::map<std::string, std::string>& options)
        : batch_size_(batch_size),
          pool_(GetDefaultPool()),
          arrow_pool_(GetArrowPool(pool_)),
          options_(options) {}

    ReaderBuilder* WithMemoryPool(const std::shared_ptr<MemoryPool>& pool) override {
        pool_ = pool;
        if (pool == nullptr) {
            arrow_pool_.reset();
        } else {
            arrow_pool_ = GetArrowPool(pool);
        }
        return this;
    }

    void SetBlobReadContext(const std::shared_ptr<BlobReadContext>& context) override {
        blob_context_ = context;
    }

    Result<std::unique_ptr<FileBatchReader>> Build(
        const std::shared_ptr<InputStream>& input_stream) const override {
        if (pool_ == nullptr) {
            return Status::Invalid("Blob reader memory pool is nullptr");
        }
        PAIMON_ASSIGN_OR_RAISE(
            bool blob_as_descriptor,
            OptionsUtils::GetValueFromMap<bool>(options_, Options::BLOB_AS_DESCRIPTOR, false));
        PAIMON_ASSIGN_OR_RAISE(bool emit_placeholder_sentinel,
                               OptionsUtils::GetValueFromMap<bool>(
                                   options_, BlobDefs::kEmitPlaceholderSentinelKey, false));
        return BlobFileBatchReader::Create(input_stream, batch_size_, blob_as_descriptor,
                                           emit_placeholder_sentinel, pool_, blob_context_,
                                           arrow_pool_);
    }

 private:
    int32_t batch_size_;
    std::shared_ptr<MemoryPool> pool_;
    std::shared_ptr<arrow::MemoryPool> arrow_pool_;
    std::map<std::string, std::string> options_;
    std::shared_ptr<BlobReadContext> blob_context_;
};

}  // namespace paimon::blob