/**
* Allocate a new stringbuffer_t. Use stringbuffer_destroy to free.
*/
-stringbuffer_t *stringbuffer_create(void)
+stringbuffer_t* stringbuffer_create(void)
{
- stringbuffer_t *sb;
-
- sb = lwalloc(sizeof(stringbuffer_t));
- sb->length = 0;
- sb->capacity = STRINGBUFFER_STARTSIZE;
- sb->str = lwalloc(sizeof(char) * STRINGBUFFER_STARTSIZE);
- memset(sb->str,0,STRINGBUFFER_STARTSIZE);
- memset(sb->buffer,0,STRINGBUFFER_WORKSIZE);
- return sb;
+ stringbuffer_t *s;
+
+ s = lwalloc(sizeof(stringbuffer_t));
+ s->str_start = lwalloc(sizeof(char) * STRINGBUFFER_STARTSIZE);
+ s->str_end = s->str_start;
+ s->capacity = STRINGBUFFER_STARTSIZE;
+ memset(s->str_start,0,STRINGBUFFER_STARTSIZE);
+ return s;
}
/**
* Free the stringbuffer_t and all memory managed within it.
*/
-void stringbuffer_destroy(stringbuffer_t *sb)
+void stringbuffer_destroy(stringbuffer_t *s)
{
- if( sb->str ) lwfree(sb->str);
- if( sb ) lwfree(sb);
+ if( s->str_start ) lwfree(s->str_start);
+ if( s ) lwfree(s);
}
/**
* without the expense of freeing and re-allocating a new
* stringbuffer_t.
*/
-void stringbuffer_clear(stringbuffer_t *sb)
+void stringbuffer_clear(stringbuffer_t *s)
{
- sb->str[0] = '\0';
- sb->length = 0;
- memset(sb->buffer,0,STRINGBUFFER_WORKSIZE);
+ s->str_start[0] = '\0';
+ s->str_end = s->str_start;
}
/**
* If necessary, expand the stringbuffer_t internal buffer to accomodate the
* specified additional size.
*/
-static void stringbuffer_makeroom(stringbuffer_t *sb, size_t length_to_add)
+static void stringbuffer_makeroom(stringbuffer_t *s, size_t size_to_add)
{
- size_t reqd_capacity = sb->capacity;
+ size_t current_size = (s->str_end - s->str_start);
+ size_t capacity = s->capacity;
+ size_t required_size = current_size + size_to_add;
- while(reqd_capacity < (length_to_add + sb->length))
- reqd_capacity *= 2;
+ while(capacity < required_size)
+ capacity *= 2;
- if( reqd_capacity > sb->capacity )
+ if( capacity > s->capacity )
{
- sb->str = lwrealloc(sb->str, sizeof(char) * reqd_capacity);
- sb->capacity = reqd_capacity;
+ s->str_start = lwrealloc(s->str_start, sizeof(char) * capacity);
+ s->capacity = capacity;
+ s->str_end = s->str_start + current_size;
}
}
/**
* Append the specified string to the stringbuffer_t.
*/
-void stringbuffer_append(stringbuffer_t *sb, const char *s)
+void stringbuffer_append(stringbuffer_t *s, const char *a)
{
- int slen = strlen(s); /* Length of string to append */
- int slen0 = slen + 1; /* Length including null terminator */
-
- stringbuffer_makeroom(sb, slen0);
-
- memcpy(sb->str + sb->length, s, slen0);
-
- sb->length += slen;
- sb->str[sb->length] = '\0';
+ int alen = strlen(a); /* Length of string to append */
+ int alen0 = alen + 1; /* Length including null terminator */
+ stringbuffer_makeroom(s, alen0);
+ memcpy(s->str_end, a, alen0);
+ s->str_end += alen;
}
/**
* the stringbuffer. The current string will be null-terminated
* within the internal string.
*/
-const char *stringbuffer_getstring(stringbuffer_t *sb)
+const char* stringbuffer_getstring(stringbuffer_t *s)
{
- return sb->str;
+ return s->str_start;
}
/**
* current state of the string. Caller is responsible for
* freeing the return value.
*/
-char *stringbuffer_getstringcopy(stringbuffer_t *sb)
+char* stringbuffer_getstringcopy(stringbuffer_t *s)
{
- char *rv;
- size_t size;
- if( sb->length <= 0 )
- return NULL;
- size = sb->length + 1;
- rv = lwalloc(size);
- memcpy(rv, sb->str, size);
- rv[sb->length] = '\0';
- return rv;
+ size_t size = (s->str_end - s->str_start) + 1;
+ char *str = lwalloc(size);
+ memcpy(str, s->str_start, size);
+ str[size - 1] = '\0';
+ return str;
}
/**
* Returns the length of the current string, not including the
* null terminator (same behavior as strlen()).
*/
-int stringbuffer_getlength(stringbuffer_t *sb)
+int stringbuffer_getlength(stringbuffer_t *s)
{
- return sb->length;
+ return (s->str_end - s->str_start);
}
/**
* Clear the stringbuffer_t and re-start it with the specified string.
*/
-void stringbuffer_set(stringbuffer_t *sb, const char *s)
+void stringbuffer_set(stringbuffer_t *s, const char *str)
{
- stringbuffer_clear(sb);
- stringbuffer_append(sb, s);
+ stringbuffer_clear(s);
+ stringbuffer_append(s, str);
}
/**
* Appends a formatted string to the current string buffer,
* using the format and argument list provided.
*/
-static void stringbuffer_avprintf(stringbuffer_t *sb, const char *fmt, va_list ap)
+static int stringbuffer_avprintf(stringbuffer_t *s, const char *fmt, va_list ap)
{
+ int maxlen = (s->capacity - (s->str_end - s->str_start));
int len = 0; /* Length of the output */
- int len0 = 0; /* Length of the output with null terminator */
va_list ap2;
+ /* Make a copy of the variadic arguments, in case we need to print twice */
va_copy(ap2, ap);
- /* Print to our static buffer */
- len = vsnprintf(sb->buffer, STRINGBUFFER_WORKSIZE, fmt, ap);
- len0 = len + 1;
-
- stringbuffer_makeroom(sb, len0);
+ /* Print to our buffer */
+ len = vsnprintf(s->str_end, maxlen, fmt, ap);
- /* This output doesn't fit in our static buffer, allocate a dynamic one */
- if( len0 > STRINGBUFFER_WORKSIZE )
- {
- char *tmpstr = lwalloc(sizeof(char) * len0);
- vsnprintf(tmpstr, len0, fmt, ap2);
- memcpy(sb->str + sb->length, tmpstr, len0);
- lwfree(tmpstr);
- }
- /* Copy the result out of the static buffer */
- else
+ /* Propogate any printing errors upwards (check errno for info) */
+ if( len < 0 )
+ return -1;
+
+ /* If we had enough space, return the number of characters printed */
+ if( len < maxlen )
{
- memcpy(sb->str + sb->length, sb->buffer, len0);
+ s->str_end += len;
+ return len;
}
- sb->length += len;
- sb->str[sb->length] = '\0';
+
+ /* We didn't have enough space! Expand the buffer. */
+ stringbuffer_makeroom(s, len + 1);
+ maxlen = (s->capacity - (s->str_end - s->str_start));
+
+ /* Try to print a second time */
+ len = vsnprintf(s->str_end, maxlen, fmt, ap2);
+
+ /* Printing error or too long still? Error! */
+ if( len < 0 || len >= maxlen )
+ return -1;
+
+ /* Move end pointer forward and return. */
+ s->str_end += len;
+ return len;
}
/**
* Appends a formatted string to the current string buffer,
* using the format and argument list provided.
*/
-void stringbuffer_aprintf(stringbuffer_t *sb, const char *fmt, ...)
+int stringbuffer_aprintf(stringbuffer_t *s, const char *fmt, ...)
{
+ int r;
va_list ap;
va_start(ap, fmt);
- stringbuffer_avprintf(sb, fmt, ap);
+ r = stringbuffer_avprintf(s, fmt, ap);
va_end(ap);
+ return r;
}
/**
* Synonym for stringbuffer_aprintf
* TODO: Remove this.
*/
-void stringbuffer_vasbappend(stringbuffer_t *sb, const char *fmt, ... )
+int stringbuffer_vasbappend(stringbuffer_t *s, const char *fmt, ... )
{
+ int r;
va_list ap;
va_start(ap, fmt);
- stringbuffer_avprintf(sb, fmt, ap);
+ r = stringbuffer_avprintf(s, fmt, ap);
va_end(ap);
+ return r;
}
\ No newline at end of file
projects / postgis / commitdiff