gearman/libgearman/vector.hpp

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 * 
 *  Libgearman library
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#pragma once

#include <cstddef>
#include <cstdlib>
#include <cstdarg>

#include "libgearman-1.0/string.h"

constexpr auto GEARMAN_VECTOR_BLOCK_SIZE = 1024 * 4;

/**
  vectors are always under our control so we make some assumptions about them.

  1) is_initialized is always valid.
  2) A string once intialized will always be, until free where we
     unset this flag.
*/
struct gearman_vector_st {
  char *end;
  char *string;
  size_t current_size;

  struct Options {
    bool is_allocated;
    bool is_initialized;
    Options() :
      is_allocated{false},
      is_initialized{true}
    { }
  } options;

  gearman_vector_st() :
    end{nullptr},
    string{nullptr},
    current_size{0}
  {
  }

  gearman_vector_st(const gearman_vector_st& copy) :
    end{nullptr},
    string{nullptr},
    current_size{0}
  {
    store(copy);
  }

  gearman_vector_st(const size_t reserve);

  ~gearman_vector_st();

  gearman_vector_st& operator=(const gearman_vector_st&) = delete;

  bool resize(const size_t);
  bool reserve(const size_t);

  int	vec_printf(const char *format__, ...); // __printflike(1, 2);
  int	vec_append_printf(const char *format__, ...); // __printflike(1, 2);

  void clear()
  {
    end= string;
    if (current_size)
    {
      string[0]= 0;
    }
  }

  const char* value() const
  {
    return string;
  }

  const char* c_str() const
  {
    return string;
  }

  const void* void_ptr() const
  {
    return (const void*)string;
  }

  bool empty() const
  {
    return string == end;
  }

  size_t capacity() const
  {
    // We tell a white lie about size since we always keep things null
    // terminated
    if (current_size == 1)
    {
      return 0;
    }

    return current_size;
  }

  char* ptr(size_t expect)
  {
    if (resize(expect +1))
    {
      end= string +expect;
      string[expect]= 0;
      return string;
    }

    return nullptr;
  }

  bool store(const gearman_vector_st&);
  bool store(const char*, const size_t);
  bool append(const char* arg_, const size_t arg_length_);
  bool append_character(const char character);

  size_t size() const;
  gearman_string_t take();

private:
  void init();
  int	vec_size_printf(const char *format__, va_list args__);
  int	vec_ptr_printf(const int required_size, const char *format__, va_list args__);
};

gearman_vector_st *gearman_string_create(gearman_vector_st *string,
                                         size_t initial_size);


gearman_vector_st *gearman_string_create(gearman_vector_st *self, 
                                         const char *str, size_t initial_size);