BLI_string: add BLI_snprintf_rlen

use when the length of the destination string is needed.

3 files changed, 59 insertions, 14 deletions

diff --git a/source/blender/blenlib/BLI_string.h b/source/blender/blenlib/BLI_string.h
index c4853e37398..e6c1cc8b4b6 100644
--- a/source/blender/blenlib/BLI_string.h
+++ b/source/blender/blenlib/BLI_string.h
@@ -59,8 +59,10 @@ char *BLI_str_quoted_substrN(const char *__restrict str, const char *__restrict
 char *BLI_replacestrN(const char *__restrict str, const char *__restrict substr_old, const char *__restrict substr_new) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL() ATTR_MALLOC;
 
 size_t BLI_snprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...) ATTR_NONNULL(1, 3) ATTR_PRINTF_FORMAT(3, 4);
+size_t BLI_snprintf_rlen(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...) ATTR_NONNULL(1, 3) ATTR_PRINTF_FORMAT(3, 4);
 
 size_t BLI_vsnprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, va_list arg) ATTR_PRINTF_FORMAT(3, 0);
+size_t BLI_vsnprintf_rlen(char *__restrict buffer, size_t maxncpy, const char *__restrict format, va_list arg) ATTR_PRINTF_FORMAT(3, 0);
 
 char *BLI_sprintfN(const char *__restrict format, ...) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1) ATTR_MALLOC ATTR_PRINTF_FORMAT(1, 2);
 
diff --git a/source/blender/blenlib/intern/string.c b/source/blender/blenlib/intern/string.c
index cc5a90dbc39..e41e52a7c6e 100644
--- a/source/blender/blenlib/intern/string.c
+++ b/source/blender/blenlib/intern/string.c
@@ -231,6 +231,30 @@ size_t BLI_vsnprintf(char *__restrict buffer, size_t maxncpy, const char *__rest
 }
 
 /**
+ * A version of #BLI_vsnprintf that returns ``strlen(buffer)``
+ */
+size_t BLI_vsnprintf_rlen(char *__restrict buffer, size_t maxncpy, const char *__restrict format, va_list arg)
+{
+	size_t n;
+
+	BLI_assert(buffer != NULL);
+	BLI_assert(maxncpy > 0);
+	BLI_assert(format != NULL);
+
+	n = (size_t)vsnprintf(buffer, maxncpy, format, arg);
+
+	if (n != -1 && n < maxncpy) {
+		/* pass */
+	}
+	else {
+		n = maxncpy - 1;
+	}
+	buffer[n] = '\0';
+
+	return n;
+}
+
+/**
  * Portable replacement for #snprintf
  */
 size_t BLI_snprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...)
@@ -250,6 +274,25 @@ size_t BLI_snprintf(char *__restrict dst, size_t maxncpy, const char *__restrict
 }
 
 /**
+ * A version of #BLI_snprintf that returns ``strlen(dst)``
+ */
+size_t BLI_snprintf_rlen(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...)
+{
+	size_t n;
+	va_list arg;
+
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
+	va_start(arg, format);
+	n = BLI_vsnprintf_rlen(dst, maxncpy, format, arg);
+	va_end(arg);
+
+	return n;
+}
+
+/**
  * Print formatted string into a newly #MEM_mallocN'd string
  * and return it.
  */
diff --git a/source/blender/blenlib/intern/timecode.c b/source/blender/blenlib/intern/timecode.c
index 0c8834008b6..7b98d7830ee 100644
--- a/source/blender/blenlib/intern/timecode.c
+++ b/source/blender/blenlib/intern/timecode.c
@@ -113,22 +113,22 @@ size_t BLI_timecode_string_from_time(
 			if (power <= 0) {
 				/* include "frames" in display */
 				if (hours) {
-					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d+%02d", neg, hours, minutes, seconds, frames);
+					rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%02d+%02d", neg, hours, minutes, seconds, frames);
 				}
 				else if (minutes) {
-					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d+%02d", neg, minutes, seconds, frames);
+					rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d+%02d", neg, minutes, seconds, frames);
 				}
 				else {
-					rlen = BLI_snprintf(str, maxncpy, "%s%d+%02d", neg, seconds, frames);
+					rlen = BLI_snprintf_rlen(str, maxncpy, "%s%d+%02d", neg, seconds, frames);
 				}
 			}
 			else {
 				/* don't include 'frames' in display */
 				if (hours) {
-					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d", neg, hours, minutes, seconds);
+					rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%02d", neg, hours, minutes, seconds);
 				}
 				else {
-					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d", neg, minutes, seconds);
+					rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d", neg, minutes, seconds);
 				}
 			}
 			break;
@@ -137,10 +137,10 @@ size_t BLI_timecode_string_from_time(
 		{
 			/* reduced SMPTE format that always shows minutes, seconds, frames. Hours only shown as needed. */
 			if (hours) {
-				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
 			}
 			else {
-				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d", neg, minutes, seconds, frames);
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%02d", neg, minutes, seconds, frames);
 			}
 			break;
 		}
@@ -156,10 +156,10 @@ size_t BLI_timecode_string_from_time(
 			const int s_pad = ms_dp + 3;
 
 			if (hours) {
-				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%0*.*f", neg, hours, minutes, s_pad, ms_dp, time);
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%0*.*f", neg, hours, minutes, s_pad, ms_dp, time);
 			}
 			else {
-				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%0*.*f", neg, minutes, s_pad,  ms_dp, time);
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%0*.*f", neg, minutes, s_pad,  ms_dp, time);
 			}
 			break;
 		}
@@ -168,10 +168,10 @@ size_t BLI_timecode_string_from_time(
 			/* only show the original seconds display */
 			/* round to whole numbers if power is >= 1 (i.e. scale is coarse) */
 			if (power <= 0) {
-				rlen = BLI_snprintf(str, maxncpy, "%.*f", 1 - power, time_seconds);
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%.*f", 1 - power, time_seconds);
 			}
 			else {
-				rlen = BLI_snprintf(str, maxncpy, "%d", iroundf(time_seconds));
+				rlen = BLI_snprintf_rlen(str, maxncpy, "%d", iroundf(time_seconds));
 			}
 			break;
 		}
@@ -179,7 +179,7 @@ size_t BLI_timecode_string_from_time(
 		default:
 		{
 			/* full SMPTE format */
-			rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
+			rlen = BLI_snprintf_rlen(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
 			break;
 		}
 	}
@@ -208,10 +208,10 @@ size_t BLI_timecode_string_from_time_simple(
 
 	/* round to whole numbers if power is >= 1 (i.e. scale is coarse) */
 	if (power <= 0) {
-		rlen = BLI_snprintf(str, maxncpy, "%.*f", 1 - power, time_seconds);
+		rlen = BLI_snprintf_rlen(str, maxncpy, "%.*f", 1 - power, time_seconds);
 	}
 	else {
-		rlen = BLI_snprintf(str, maxncpy, "%d", iroundf(time_seconds));
+		rlen = BLI_snprintf_rlen(str, maxncpy, "%d", iroundf(time_seconds));
 	}
 
 	return rlen;