diff options
| -rw-r--r-- | src/glsl/ralloc.c | 27 | ||||
| -rw-r--r-- | src/glsl/ralloc.h | 57 |
2 files changed, 80 insertions, 4 deletions
diff --git a/src/glsl/ralloc.c b/src/glsl/ralloc.c index fb48a91c564..2967598aecb 100644 --- a/src/glsl/ralloc.c +++ b/src/glsl/ralloc.c @@ -439,7 +439,27 @@ ralloc_asprintf_append(char **str, const char *fmt, ...) bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args) { - size_t existing_length, new_length; + assert(str != NULL); + size_t existing_length = *str ? strlen(*str) : 0; + return ralloc_vasprintf_rewrite_tail(str, existing_length, fmt, args); +} + +bool +ralloc_asprintf_rewrite_tail(char **str, size_t start, const char *fmt, ...) +{ + bool success; + va_list args; + va_start(args, fmt); + success = ralloc_vasprintf_rewrite_tail(str, start, fmt, args); + va_end(args); + return success; +} + +bool +ralloc_vasprintf_rewrite_tail(char **str, size_t start, const char *fmt, + va_list args) +{ + size_t new_length; char *ptr; assert(str != NULL); @@ -450,14 +470,13 @@ ralloc_vasprintf_append(char **str, const char *fmt, va_list args) return true; } - existing_length = strlen(*str); new_length = printf_length(fmt, args); - ptr = resize(*str, existing_length + new_length + 1); + ptr = resize(*str, start + new_length + 1); if (unlikely(ptr == NULL)) return false; - vsnprintf(ptr + existing_length, new_length + 1, fmt, args); + vsnprintf(ptr + start, new_length + 1, fmt, args); *str = ptr; return true; } diff --git a/src/glsl/ralloc.h b/src/glsl/ralloc.h index d5338152f10..1324f3466bb 100644 --- a/src/glsl/ralloc.h +++ b/src/glsl/ralloc.h @@ -314,9 +314,60 @@ char *ralloc_asprintf (const void *ctx, const char *fmt, ...); char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args); /** + * Rewrite the tail of an existing string, starting at a given index. + * + * Overwrites the contents of *str starting at \p start with newly formatted + * text, including a new null-terminator. Allocates more memory as necessary. + * + * This can be used to append formatted text when the length of the existing + * string is already known, saving a strlen() call. + * + * \sa ralloc_asprintf_append + * + * \param str The string to be updated. + * \param start The index to start appending new data at. + * \param fmt A printf-style formatting string + * + * \p str will be updated to the new pointer unless allocation fails. + * + * \return True unless allocation failed. + */ +bool ralloc_asprintf_rewrite_tail(char **str, size_t start, + const char *fmt, ...); + +/** + * Rewrite the tail of an existing string, starting at a given index. + * + * Overwrites the contents of *str starting at \p start with newly formatted + * text, including a new null-terminator. Allocates more memory as necessary. + * + * This can be used to append formatted text when the length of the existing + * string is already known, saving a strlen() call. + * + * \sa ralloc_vasprintf_append + * + * \param str The string to be updated. + * \param start The index to start appending new data at. + * \param fmt A printf-style formatting string + * \param args A va_list containing the data to be formatted + * + * \p str will be updated to the new pointer unless allocation fails. + * + * \return True unless allocation failed. + */ +bool ralloc_vasprintf_rewrite_tail(char **str, size_t start, const char *fmt, + va_list args); + +/** * Append formatted text to the supplied string. * + * This is equivalent to + * \code + * ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...) + * \endcode + * * \sa ralloc_asprintf + * \sa ralloc_asprintf_rewrite_tail * \sa ralloc_strcat * * \p str will be updated to the new pointer unless allocation fails. @@ -328,7 +379,13 @@ bool ralloc_asprintf_append (char **str, const char *fmt, ...); /** * Append formatted text to the supplied string, given a va_list. * + * This is equivalent to + * \code + * ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args) + * \endcode + * * \sa ralloc_vasprintf + * \sa ralloc_vasprintf_rewrite_tail * \sa ralloc_strcat * * \p str will be updated to the new pointer unless allocation fails. |