$41 GRAYBYTE WORDPRESS FILE MANAGER $53

/*
  +----------------------------------------------------------------------+
  | Swoole                                                               |
  +----------------------------------------------------------------------+
  | This source file is subject to version 2.0 of the Apache license,    |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.apache.org/licenses/LICENSE-2.0.html                      |
  | If you did not receive a copy of the Apache2.0 license and are unable|
  | to obtain it through the world-wide-web, please send a note to       |
  | [email protected] so we can mail you a copy immediately.            |
  +----------------------------------------------------------------------+
  | Author: Tianfeng Han  <[email protected]>                             |
  +----------------------------------------------------------------------+
*/

#pragma once

#include "swoole_memory.h"
#include "swoole_lock.h"

#include <csignal>

#include <vector>
#include <unordered_map>

//#define SW_TABLE_DEBUG   0
#define SW_TABLE_FORCE_UNLOCK_TIME 2000  // milliseconds
#define SW_TABLE_USE_PHP_HASH
#define SW_TABLE_MAX_ROW_SIZE 0x80000000

namespace swoole {
typedef uint32_t TableStringLength;
typedef uint64_t (*HashFunc)(const char *key, size_t len);

struct TableColumn;

struct TableRow {
    sw_atomic_t lock_;
    pid_t lock_pid;
    /**
     * 1:used, 0:empty
     */
    uint8_t active;
    uint8_t key_len;
    /**
     * next slot
     */
    TableRow *next;
    /**
     * Hash Key
     */
    char key[SW_TABLE_KEY_SIZE];
    char data[0];

    void lock();

    void unlock() {
        sw_spinlock_release(&lock_);
    }

    void clear() {
        sw_memset_zero((char *) &lock_pid, sizeof(TableRow) - offsetof(TableRow, lock_pid));
    }

    void set_value(const TableColumn *col, const void *value, size_t vlen);
    void get_value(const TableColumn *col, double *dval) const;
    void get_value(const TableColumn *col, long *lval) const;
    void get_value(const TableColumn *col, char **strval, TableStringLength *strlen);
};

struct TableIterator {
    size_t row_memory_size_;
    uint32_t absolute_index = 0;
    uint32_t collision_index = 0;
    TableRow *current_;
    Mutex *mutex_;

    explicit TableIterator(size_t row_size);
    ~TableIterator();

    void reset();

    void lock() const {
        mutex_->lock();
    }

    void unlock() const {
        mutex_->unlock();
    }
};

enum TableFlag {
    SW_TABLE_FLAG_NEW_ROW = 1,
    SW_TABLE_FLAG_CONFLICT = 1u << 1,
};

struct TableColumn {
    enum Type {
        TYPE_INT = 1,
        TYPE_FLOAT,
        TYPE_STRING,
    };

    Type type;
    uint32_t size;
    std::string name;
    size_t index;

    TableColumn(const std::string &_name, Type _type, size_t _size);

    void clear(TableRow *row) const;
};

class Table {
    std::unordered_map<std::string, TableColumn *> *column_map;
    Mutex *mutex;
    size_t size;
    size_t mask;
    size_t item_size;
    size_t memory_size;
    float conflict_proportion;

    /**
     * total rows that in active state(shm)
     */
    sw_atomic_t row_num;

    TableRow **rows;
    FixedPool *pool;

    TableIterator *iterator;
    HashFunc hash_func;
    bool created;

    void *memory;

  public:
    std::vector<TableColumn *> *column_list;

    size_t conflict_count;
    sw_atomic_long_t insert_count;
    sw_atomic_long_t delete_count;
    sw_atomic_long_t update_count;
    uint32_t conflict_max_level;

    Table() = delete;
    ~Table() = delete;

    static Table *make(uint32_t rows_size, float conflict_proportion);
    size_t calc_memory_size() const;
    size_t get_memory_size() const;
    uint32_t get_available_slice_num() const;
    uint32_t get_total_slice_num() const;
    bool create();
    bool add_column(const std::string &name, enum TableColumn::Type type, size_t size);
    TableColumn *get_column(const std::string &key) const;
    TableRow *set(const char *key, uint16_t keylen, TableRow **rowlock, int *out_flags);
    TableRow *get(const char *key, uint16_t keylen, TableRow **rowlock) const;
    bool exists(const char *key, uint16_t keylen) const;
    bool del(const char *key, uint16_t keylen);
    void forward() const;
    // release shared memory
    void destroy();

    bool is_created() const {
        return created;
    }

    bool ready() const {
        return memory != nullptr;
    }

    void set_hash_func(HashFunc _fn) {
        hash_func = _fn;
    }

    size_t get_size() const {
        return size;
    }

    float get_conflict_proportion() const {
        return conflict_proportion;
    }

    size_t get_column_size() const {
        return column_map->size();
    }

    TableRow *get_by_index(uint32_t index) const {
        TableRow *row = rows[index];
        return row->active ? row : nullptr;
    }

    size_t count() const {
        return row_num;
    }

    bool exists(const std::string &key) const {
        return exists(key.c_str(), key.length());
    }

    TableRow *current() const {
        return iterator->current_;
    }

    void rewind() const {
        iterator->lock();
        iterator->reset();
        iterator->unlock();
    }

    void clear_row(TableRow *row) const {
        for (auto &i : *column_list) {
            i->clear(row);
        }
    }

  private:
    TableRow *hash(const char *key, int keylen) const {
        uint64_t hashv = hash_func(key, keylen);
        uint64_t index = hashv & mask;
        assert(index < size);
        return rows[index];
    }

    TableRow *alloc_row() const {
        lock();
        const auto new_row = static_cast<TableRow *>(pool->alloc(0));
        unlock();
        return new_row;
    }

    void free_row(TableRow *tmp) const {
        lock();
        tmp->clear();
        pool->free(tmp);
        unlock();
    }

    static void check_key_length(uint16_t *keylen) {
        if (*keylen >= SW_TABLE_KEY_SIZE) {
            *keylen = SW_TABLE_KEY_SIZE - 1;
        }
    }

    void init_row(TableRow *new_row, const char *key, int keylen) {
        sw_memset_zero(reinterpret_cast<char *>(new_row) + offsetof(TableRow, active),
                       sizeof(TableRow) - offsetof(TableRow, active));
        memcpy(new_row->key, key, keylen);
        new_row->key[keylen] = '\0';
        new_row->key_len = keylen;
        new_row->active = 1;
        sw_atomic_fetch_add(&(row_num), 1);
    }

    int lock() const {
        return mutex->lock();
    }

    int unlock() const {
        return mutex->unlock();
    }
};
}  // namespace swoole