ut0mem.h

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/** @file include/ut0mem.h
 Memory primitives
 
 Created 5/30/1994 Heikki Tuuri
 ************************************************************************/
 
#ifndef ut0mem_h
#define ut0mem_h
 
#include "univ.i"
#ifndef UNIV_HOTBACKUP
#include "os0event.h"
#include "ut0mutex.h"
#endif /* !UNIV_HOTBACKUP */
 
/** Wrapper for memcpy(3).  Copy memory area when the source and
target are not overlapping.
@param[in,out]  dest    copy to
@param[in]      src     copy from
@param[in]      n       number of bytes to copy
@return dest */
static inline void *ut_memcpy(void *dest, const void *src, ulint n);
 
/** Wrapper for memmove(3).  Copy memory area when the source and
target are overlapping.
@param[in,out]  dest    Move to
@param[in]      src     Move from
@param[in]      n       number of bytes to move
@return dest */
static inline void *ut_memmove(void *dest, const void *src, ulint n);
 
/** Wrapper for memcmp(3).  Compare memory areas.
@param[in]      str1    first memory block to compare
@param[in]      str2    second memory block to compare
@param[in]      n       number of bytes to compare
@return negative, 0, or positive if str1 is smaller, equal,
                or greater than str2, respectively. */
static inline int ut_memcmp(const void *str1, const void *str2, ulint n);
 
/** Wrapper for strcpy(3).  Copy a NUL-terminated string.
@param[in,out]  dest    Destination to copy to
@param[in]      src     Source to copy from
@return dest */
static inline char *ut_strcpy(char *dest, const char *src);
 
/** Wrapper for strlen(3).  Determine the length of a NUL-terminated string.
@param[in]      str     string
@return length of the string in bytes, excluding the terminating NUL */
static inline ulint ut_strlen(const char *str);
 
/** Wrapper for strcmp(3).  Compare NUL-terminated strings.
@param[in]      str1    first string to compare
@param[in]      str2    second string to compare
@return negative, 0, or positive if str1 is smaller, equal,
                or greater than str2, respectively. */
static inline int ut_strcmp(const char *str1, const char *str2);
 
/** Copies up to size - 1 characters from the NUL-terminated string src to
 dst, NUL-terminating the result. Returns strlen(src), so truncation
 occurred if the return value >= size.
 @return strlen(src) */
ulint ut_strlcpy(char *dst,       /*!< in: destination buffer */
                 const char *src, /*!< in: source buffer */
                 ulint size);     /*!< in: size of destination buffer */
 
/********************************************************************
Concatenate 3 strings.*/
char *ut_str3cat(
    /* out, own: concatenated string, must be
    freed with ut::free() */
    const char *s1,  /* in: string 1 */
    const char *s2,  /* in: string 2 */
    const char *s3); /* in: string 3 */
 
/** Converts a raw binary data to a NUL-terminated hex string. The output is
truncated if there is not enough space in "hex", make sure "hex_size" is at
least (2 * raw_size + 1) if you do not want this to happen. Returns the actual
number of characters written to "hex" (including the NUL).
@param[in]      raw             raw data
@param[in]      raw_size        "raw" length in bytes
@param[out]     hex             hex string
@param[in]      hex_size        "hex" size in bytes
@return number of chars written */
static inline ulint ut_raw_to_hex(const void *raw, ulint raw_size, char *hex,
                                  ulint hex_size);
 
/** Adds single quotes to the start and end of string and escapes any quotes by
doubling them. Returns the number of bytes that were written to "buf"
(including the terminating NUL). If buf_size is too small then the trailing
bytes from "str" are discarded.
@param[in]      str             string
@param[in]      str_len         string length in bytes
@param[out]     buf             output buffer
@param[in]      buf_size        output buffer size in bytes
@return number of bytes that were written */
static inline ulint ut_str_sql_format(const char *str, ulint str_len, char *buf,
                                      ulint buf_size);
 
namespace ut {
/** Checks if the pointer has address aligned properly for a given type.
@param[in]  ptr   The pointer, address of which we want to check if it could be
                  pointing to object of type T.
@return true iff ptr address is aligned w.r.t. alignof(T) */
template <typename T>
bool is_aligned_as(void const *const ptr) {
  /* Implementation note: the type of the argument of this function needs to be
  void *, not T *, because, due to C++ rules, a pointer of type T* needs to be
  aligned. In other words, compiler could optimize out the whole function. */
  return reinterpret_cast<uintptr_t>(ptr) % alignof(T) == 0;
}
/** Checks if memory range is all zeros.
@param[in]  start            The pointer to first byte of a buffer
@param[in]  number_of_bytes  The number of bytes in the buffer
@return true if and only if `number_of_bytes` bytes pointed by `start` are all
zeros. */
[[nodiscard]] inline bool is_zeros(const void *start, size_t number_of_bytes) {
  auto *first_byte = reinterpret_cast<const char *>(start);
  return number_of_bytes == 0 ||
         (*first_byte == 0 &&
          std::memcmp(first_byte, first_byte + 1, number_of_bytes - 1) == 0);
}
 
}  // namespace ut
#include "ut0mem.ic"
 
#endif