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/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2010 Joshua Haberman. See LICENSE for details.
*/
#include "upb_string.h"
#include <stdlib.h>
#ifdef __GLIBC__
#include <malloc.h>
#elif defined(__APPLE__)
#include <malloc/malloc.h>
#endif
static uint32_t upb_round_up_pow2(uint32_t v) {
// http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;
return v;
}
upb_string *upb_string_new() {
upb_string *str = malloc(sizeof(*str));
str->ptr = NULL;
str->cached_mem = NULL;
#ifndef UPB_HAVE_MSIZE
str->size = 0;
#endif
str->src = NULL;
upb_atomic_refcount_init(&str->refcount, 1);
return str;
}
uint32_t upb_string_size(upb_string *str) {
#ifdef __GLIBC__
return malloc_usable_size(str->cached_mem);
#elif defined(__APPLE__)
return malloc_size(str->cached_mem);
#else
return str->size;
#endif
}
static void upb_string_release(upb_string *str) {
if(str->src) {
upb_string_unref(str->src);
str->src = NULL;
}
}
void _upb_string_free(upb_string *str) {
if(str->cached_mem) free(str->cached_mem);
upb_string_release(str);
free(str);
}
upb_string *upb_string_tryrecycle(upb_string *str) {
if(str == NULL || upb_atomic_read(&str->refcount) > 1) {
return upb_string_new();
} else {
str->ptr = NULL;
upb_string_release(str);
return str;
}
}
char *upb_string_getrwbuf(upb_string *str, upb_strlen_t len) {
assert(str->ptr == NULL);
uint32_t size = upb_string_size(str);
if (size < len) {
size = upb_round_up_pow2(len);
str->cached_mem = realloc(str->cached_mem, size);
#ifndef UPB_HAVE_MSIZE
str->size = size;
#endif
}
str->len = len;
str->ptr = str->cached_mem;
return str->cached_mem;
}
void upb_string_substr(upb_string *str, upb_string *target_str,
upb_strlen_t start, upb_strlen_t len) {
if(str->ptr) *(char*)0 = 0;
assert(str->ptr == NULL);
str->src = upb_string_getref(target_str);
str->ptr = upb_string_getrobuf(target_str) + start;
str->len = len;
}
void upb_string_vprintf(upb_string *str, const char *format, va_list args) {
// Try once without reallocating. We have to va_copy because we might have
// to call vsnprintf again.
uint32_t size = UPB_MAX(upb_string_size(str), 16);
char *buf = upb_string_getrwbuf(str, size);
va_list args_copy;
va_copy(args_copy, args);
uint32_t true_size = vsnprintf(buf, size, format, args_copy);
va_end(args_copy);
if (true_size >= size) {
// Need to reallocate. We reallocate even if the sizes were equal,
// because snprintf excludes the terminating NULL from its count.
// We don't care about the terminating NULL, but snprintf might
// bail out of printing even other characters if it doesn't have
// enough space to write the NULL also.
str = upb_string_tryrecycle(str);
buf = upb_string_getrwbuf(str, true_size + 1);
vsnprintf(buf, true_size + 1, format, args);
}
str->len = true_size;
}
upb_string *upb_string_asprintf(const char *format, ...) {
upb_string *str = upb_string_new();
va_list args;
va_start(args, format);
upb_string_vprintf(str, format, args);
va_end(args);
return str;
}
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