String

Header file

mln_string.h

Module

string

Structure

typedef struct {
    mln_u8ptr_t  data; //string content
    mln_u64_t    len; //string length
    mln_uauto_t  data_ref:1; //whether data is referenced
    mln_uauto_t  pool:1; //is allocated from memory pool
    mln_uauto_t  ref:30; //reference counter
} mln_string_t;

Functions/Macros

mln_string

mln_string(str)

Description: Create a mln_string_t object using the string constant str. Used to initialize the mln_string_t variable while defining it.

Return value: mln_string_t type structure

Example:

void foo()
{
  mln_string_t s = mln_string("Hello");
}

mln_string_set

mln_string_set(pstr, s)

Description: Used to assign the string s to the structure pointed to by the mln_string_t pointer pstr. At this point, the data_ref member will be set to 1.

Return value: none

Example:

void foo()
{
  char text[] = "hello";
  mln_string_t s;
  mln_string_set(&s, text);
}

mln_string_nset

mln_string_nset(pstr, s, n)

Description: Same as mln_string_set, except that mln_string_t pointed to by pstr only records the first n bytes of s.

Return value: none

Example:

void foo()
{
  char text[] = "hello world";
  mln_string_t s;
  mln_string_nset(&s, text, 5); //利用mln_log的%S进行输出时，仅会输出hello
}

mln_string_ref

mln_string_ref(pstr)

Description: Add 1 to the ref member of the mln_string_t structure pointed to by pstr to directly refer to the pstr memory structure. When freeing memory, memory is not actually freed when the reference count is greater than 1.

Return value: pointer of type mln_string_t

void foo(mln_string_t s)
{
  mln_string_t *ref = mln_string_ref(s); //此时ref与s的内存地址完全相同
  ...
}

mln_string_free

mln_string_free(pstr)

Description: Release the mln_string_t structure memory pointed to by ptrs. If ref is greater than 1, only the reference count will be decremented. If data_ref is 1, the memory pointed to by the data member will not be released, otherwise data will be released. member memory, followed by freeing pstr memory. When releasing, it will judge whether to release back to the memory pool or return to the malloc library according to the pool member.

Return value: none

mln_string_new

mln_string_t *mln_string_new(const char *s);

Description: Create a string structure based on the string constant s. At this time, the memory of the new string structure and its data part is allocated by the malloc library, and the content of s is copied into the data member.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_pool_new

mln_string_t *mln_string_pool_new(mln_alloc_t *pool, const char *s);

Description: Consistent with the mln_string_new function, only the memory is allocated from the memory pool pointed to by pool.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_buf_new

mln_string_t *mln_string_buf_new(mln_u8ptr_t buf, mln_u64_t len);

Description: Create a string structure using buf and len as string contents. Note: buf should be allocated through malloc family functions and cannot be released externally.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_buf_pool_new

mln_string_t *mln_string_buf_pool_new(mln_alloc_t *pool, mln_u8ptr_t buf, mln_u64_t len);

Description: Create a string structure using buf and len as string contents. Note: buf should be allocated from pool and cannot be freed externally.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_dup

mln_string_t *mln_string_dup(mln_string_t *str);

Description: A complete copy of str whose memory is allocated by malloc.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_pool_dup

mln_string_t *mln_string_pool_dup(mln_alloc_t *pool, mln_string_t *str);

Description: Consistent with the mln_string_dup function, only memory is allocated from the memory pool pointed to by pool.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_alloc

mln_string_t *mln_string_alloc(mln_s32_t size);

Description: Create a new string object and pre-allocate a buffer of size bytes.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_pool_alloc

mln_string_t *mln_string_pool_alloc(mln_alloc_t *pool, mln_s32_t size);

Description: Create a new string object and pre-allocate a buffer of size bytes. The difference with mln_string_alloc is that all memory is allocated from the memory pool pool.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_const_ndup

mln_string_t *mln_string_const_ndup(char *str, mln_s32_t size);

Description: Creates a new string object and copies only the first size bytes of data in str.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_ref_dup

mln_string_t *mln_string_ref_dup(mln_string_t *str);

Description: Create a new string structure, but the data member in the structure points to the address pointed to by the data member in str, and the data_ref in the new structure will be set.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_const_ref_dup

mln_string_t *mln_string_const_ref_dup(char *s);

Description: Create a new string structure, but the data member in the structure points to s, and the data_ref in the new structure will be set.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_strseqcmp

int mln_string_strseqcmp(mln_string_t *s1, mln_string_t *s2);

Description: Compare the data of s1 and s2, if the short side exactly matches the front of the long side, then the long side is greater than the short side.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

Example:

int main(void)
{
  mln_string_t s1 = mln_string("abcd");
  mln_string_t s2 = mln_string("abcdefg");
  printf("%d", mln_string_strseqcmp(&s1, &s2)); //-1
  return 0;
}

mln_string_strcmp

int mln_string_strcmp(mln_string_t *s1, mln_string_t *s2);

Description: Compare the size of data in s1 and s2.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_const_strcmp

int mln_string_const_strcmp(mln_string_t *s1, char *s2);

Description: Compare the data recorded by s1 with the size of s2.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_strncmp

int mln_string_strncmp(mln_string_t *s1, mln_string_t *s2, mln_u32_t n);

Description: Compare the size of the first n bytes of s1 and s2.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_const_strncmp

int mln_string_const_strncmp(mln_string_t *s1, char *s2, mln_u32_t n);

Description: Compare the size of the data recorded by s1 with the size of the first n bytes of s2.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_strcasecmp

int mln_string_strcasecmp(mln_string_t *s1, mln_string_t *s2);

Description: Compare the size of s1 and s2 data, ignoring case.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_const_strcasecmp

int mln_string_const_strcasecmp(mln_string_t *s1, char *s2);

Description: Compare the size of the data recorded by s1 with that of s2, ignoring case.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_const_strncasecmp

int mln_string_const_strncasecmp(mln_string_t *s1, char *s2, mln_u32_t n);

描述：比较s1所记录的数据与s2的前n个字节的大小，且忽略大小写。

返回值：

• -1 - s1比s2小
• 1 - s1比s2大
• 0 - 二者相同

mln_string_strncasecmp

int mln_string_strncasecmp(mln_string_t *s1, mln_string_t *s2, mln_u32_t n);

Description: Compare the size of the first n bytes of data recorded by s1 and s2, ignoring case.

return value:

• -1 - s1 is smaller than s2
• 1 - s1 is larger than s2
• 0 - both are the same

mln_string_strstr

char *mln_string_strstr(mln_string_t *text, mln_string_t *pattern);

Description: Match the data recorded by text with the same starting address as the data in pattern.

Return value: If the match is successful, return the corresponding address in the address pointed to by the data member of text; otherwise, return NULL.

mln_string_const_strstr

char *mln_string_const_strstr(mln_string_t *text, char *pattern);

Description: Matches the same starting address as pattern in the data recorded by text.

Return value: If the match is successful, return the corresponding address in the address pointed to by the data member of text; otherwise, return NULL.

mln_string_new_strstr

mln_string_t *mln_string_new_strstr(mln_string_t *text, mln_string_t *pattern);

Description: Same function as mln_string_strstr, but returns a string wrapped by mln_string_t structure.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_new_const_strstr

mln_string_t *mln_string_new_const_strstr(mln_string_t *text, char *pattern);

Description: Same function as mln_string_const_strstr, but returns a string wrapped by mln_string_t structure.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_kmp

char *mln_string_kmp(mln_string_t *text, mln_string_t *pattern);

Description: Same function as mln_string_strstr, but implemented by KMP algorithm. The applicable scenario of the KMP algorithm is when there are many strings with the same prefix as the pattern in text. For example: text contains aaaaaaaaaabc, pattern contains ab, at this time, the performance of KMP algorithm will be higher than that of naive algorithm.

Return value: If the match is successful, return the corresponding address in the address pointed to by the data member of text; otherwise, return NULL.

mln_string_const_kmp

char *mln_string_const_kmp(mln_string_t *text, char *pattern);

Description: Same function as mln_string_kmp, but pattern is a character pointer type.

Return value: If the match is successful, return the corresponding address in the address pointed to by the data member of text; otherwise, return NULL.

mln_string_new_kmp

mln_string_t *mln_string_new_kmp(mln_string_t *text, mln_string_t *pattern);

Description: Consistent with the mln_string_kmp function, but returns the data wrapped by the mln_string_t structure.

Return value: return mln_string_t pointer on success, NULL on failure.

mln_string_new_const_kmp

mln_string_t *mln_string_new_const_kmp(mln_string_t *text, char *pattern);

Description: Consistent with the mln_string_const_kmp function, but returns the data wrapped by the mln_string_t structure.

Return value: return mln_string_t pointer on success, NULL on failure.

mln_string_slice

mln_string_t *mln_string_slice(mln_string_t *s, const char *sep_array/*ended by \0*/);

Description: seq_array is a zero-terminated array of characters, where each character of the array is a delimiter. The function will scan the data s. When any character in seq_array is encountered in the data, it will be divided. When multiple characters are encountered in a row, it will only be divided once, and after division, the delimiter will not appear in the in the split string.

Return value: return mln_string_t array on success, otherwise return NULL. The len of the last element of the array is 0.

Example:

int main(void)
{
  mln_string_t s = mln_string("abc-def-=ghi");
  mln_string_t *str, *arr = mln_string_slice(&s, "-=");
  for (str = arr; str->len; ++str) {
    mln_log(debug, "%S", str);
  }
  mln_string_slice_free(arr);
  return 0;
}

mln_string_slice_free

void mln_string_slice_free(mln_string_t *array);

Description: Free the mln_string_t array created by the mln_string_slice function.

Return value: none

mln_string_strcat

mln_string_t *mln_string_strcat(mln_string_t *s1, mln_string_t *s2);

Description: Create a new mln_string_t structure whose data is the result of concatenating s1 and s2 in this order.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_pool_strcat

mln_string_t *mln_string_pool_strcat(mln_alloc_t *pool, mln_string_t *s1, mln_string_t *s2);

Description: Consistent with the mln_string_strcat function, only the memory used by the new structure is allocated by the memory pool pointed to by pool.

Return value: return mln_string_t pointer on success, otherwise return NULL.

mln_string_trim

mln_string_t *mln_string_trim(mln_string_t *s, mln_string_t *mask);

Description: Remove whitespace (or other characters) specified by mask at the beginning and end of the string.

Return value: pointer to the stripped string mln_string_t allocated by the heap.

mln_string_pool_trim

mln_string_t *mln_string_pool_trim(mln_alloc_t *pool, mln_string_t *s, mln_string_t *mask);

Description: Same function as mln_string_trim.

Return value: The stripped string mln_string_t pointer allocated on the memory pool specified by pool.

mln_string_upper

void mln_string_upper(mln_string_t *s);

Description: Convert all English letters in the string s to uppercase.

Return value: none

mln_string_lower

void mln_string_lower(mln_string_t *s);

Description: Convert all English letters in the string s to lowercase.

Return value: none