src/paimon/common/file_index/rangebitmap/dictionary/chunk.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 <fmt/format.h>

#include <memory>

#include "paimon/memory/bytes.h"
#include "paimon/predicate/literal.h"
#include "paimon/result.h"

namespace paimon {

class Chunk {
 public:
    virtual ~Chunk() = default;

    virtual Result<bool> TryAdd(const Literal& key) = 0;

    /// Finds a key within this chunk using binary search.
    ///
    /// @param key The key to search for
    /// @return index of the search key, if it is contained in the chunk;
    ///         otherwise, -(insertion_point + 1). The insertion point
    ///         is defined as the point at which the key would be inserted into the chunk:
    ///         the index of the first element greater than the key, or the chunk's size
    ///         if all elements in the chunk are less than the specified key. Note that
    ///         this guarantees that the return value will be >= 0 if and only if the key is found.
    virtual Result<int32_t> Find(const Literal& key) {
        PAIMON_ASSIGN_OR_RAISE(int32_t cmp_with_key, CompareKey(Key(), key));
        if (cmp_with_key == 0) {
            return Code();
        }
        int32_t low = 0;
        int32_t high = Size() - 1;
        const int32_t base = Code() + 1;
        while (low <= high) {
            const int32_t mid = low + (high - low) / 2;
            PAIMON_ASSIGN_OR_RAISE(Literal key_at_mid, GetKey(mid));
            PAIMON_ASSIGN_OR_RAISE(int32_t cmp, CompareKey(key_at_mid, key));
            if (cmp < 0) {
                low = mid + 1;
            } else if (cmp > 0) {
                high = mid - 1;
            } else {
                return base + mid;
            }
        }
        return -(base + low + 1);
    }

    virtual Result<Literal> Find(int32_t code) {
        const auto current = Code();
        if (current == code) {
            return Key();
        }
        const auto index = code - current - 1;
        if (index < 0 || index >= Size()) {
            return Status::Invalid(fmt::format("Invalid Code: {}", code));
        }
        return GetKey(index);
    }

    virtual const Literal& Key() const = 0;

    virtual int32_t Code() const = 0;

    virtual int32_t Offset() const = 0;

    virtual void SetOffset(int32_t offset) = 0;

    virtual int32_t Size() const = 0;

    virtual Result<PAIMON_UNIQUE_PTR<Bytes>> SerializeChunk() const = 0;

    virtual Result<PAIMON_UNIQUE_PTR<Bytes>> SerializeKeys() const = 0;

 protected:
    virtual Result<Literal> GetKey(int32_t index) = 0;

    virtual Result<int32_t> CompareKey(const Literal& lhs, const Literal& rhs) = 0;
};

}  // namespace paimon