[FFmpeg-cvslog] lavu/bprint: implement av_bprint_strftime().
Nicolas George
git at videolan.org
Sat Nov 17 19:56:41 CET 2012
ffmpeg | branch: master | Nicolas George <nicolas.george at normalesup.org> | Sat Nov 10 16:05:53 2012 +0100| [4cd74c81435919e7ed1a30de5d947d3077ac9299] | committer: Nicolas George
lavu/bprint: implement av_bprint_strftime().
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4cd74c81435919e7ed1a30de5d947d3077ac9299
---
doc/APIchanges | 3 +++
libavutil/bprint.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++
libavutil/bprint.h | 16 ++++++++++++++-
libavutil/version.h | 2 +-
tests/ref/fate/bprint | 2 ++
5 files changed, 74 insertions(+), 2 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 1d10af5..57be6ba 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil: 2012-10-22
API changes, most recent first:
+2012-11-17 - xxxxxxx - lavu 52.8.100 - bprint.h
+ Add av_bprint_strftime().
+
2012-11-15 - xxxxxxx - lavu 52.7.100 - opt.h
Add av_opt_get_key_value().
diff --git a/libavutil/bprint.c b/libavutil/bprint.c
index 9d8e7c1..4684ab4 100644
--- a/libavutil/bprint.c
+++ b/libavutil/bprint.c
@@ -21,6 +21,7 @@
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
+#include <time.h>
#include "avassert.h"
#include "bprint.h"
#include "common.h"
@@ -129,6 +130,48 @@ void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
av_bprint_grow(buf, n);
}
+void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm)
+{
+ unsigned room;
+ size_t l;
+
+ if (!*fmt)
+ return;
+ while (1) {
+ room = av_bprint_room(buf);
+ if (room && (l = strftime(buf->str + buf->len, room, fmt, tm)))
+ break;
+ /* strftime does not tell us how much room it would need: let us
+ retry with twice as much until the buffer is large enough */
+ room = !room ? strlen(fmt) + 1 :
+ room <= INT_MAX / 2 ? room * 2 : INT_MAX;
+ if (av_bprint_alloc(buf, room)) {
+ /* impossible to grow, try to manage something useful anyway */
+ room = av_bprint_room(buf);
+ if (room < 1024) {
+ /* if strftime fails because the buffer has (almost) reached
+ its maximum size, let us try in a local buffer; 1k should
+ be enough to format any real date+time string */
+ char buf2[1024];
+ if ((l = strftime(buf2, sizeof(buf2), fmt, tm))) {
+ av_bprintf(buf, "%s", buf2);
+ return;
+ }
+ }
+ if (room) {
+ /* if anything else failed and the buffer is not already
+ truncated, let us add a stock string and force truncation */
+ static const char txt[] = "[truncated strftime output]";
+ memset(buf->str + buf->len, '!', room);
+ memcpy(buf->str + buf->len, txt, FFMIN(sizeof(txt) - 1, room));
+ av_bprint_grow(buf, room); /* force truncation */
+ }
+ return;
+ }
+ }
+ av_bprint_grow(buf, l);
+}
+
void av_bprint_get_buffer(AVBPrint *buf, unsigned size,
unsigned char **mem, unsigned *actual_size)
{
@@ -201,6 +244,7 @@ int main(void)
{
AVBPrint b;
char buf[256];
+ struct tm testtime = { .tm_year = 100, .tm_mon = 11, .tm_mday = 20 };
av_bprint_init(&b, 0, -1);
bprint_pascal(&b, 5);
@@ -235,6 +279,15 @@ int main(void)
bprint_pascal(&b, 25);
printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(buf), b.len);
+ av_bprint_init(&b, 0, -1);
+ av_bprint_strftime(&b, "%Y-%m-%d", &testtime);
+ printf("strftime full: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str);
+ av_bprint_finalize(&b, NULL);
+
+ av_bprint_init(&b, 0, 8);
+ av_bprint_strftime(&b, "%Y-%m-%d", &testtime);
+ printf("strftime truncated: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str);
+
return 0;
}
diff --git a/libavutil/bprint.h b/libavutil/bprint.h
index c09b61f..f3915fe 100644
--- a/libavutil/bprint.h
+++ b/libavutil/bprint.h
@@ -116,7 +116,7 @@ void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max);
void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size);
/**
- * Append a formated string to a print buffer.
+ * Append a formatted string to a print buffer.
*/
void av_bprintf(AVBPrint *buf, const char *fmt, ...) av_printf_format(2, 3);
@@ -125,6 +125,20 @@ void av_bprintf(AVBPrint *buf, const char *fmt, ...) av_printf_format(2, 3);
*/
void av_bprint_chars(AVBPrint *buf, char c, unsigned n);
+struct tm;
+/**
+ * Append a formatted date and time to a print buffer.
+ *
+ * param buf bprint buffer to use
+ * param fmt date and time format string, see strftime()
+ * param tm broken-down time structure to translate
+ *
+ * @note due to poor design of the standard strftime function, it may
+ * produce poor results if the format string expands to a very long text and
+ * the bprint buffer is near the limit stated by the size_max option.
+ */
+void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm);
+
/**
* Allocate bytes in the buffer for external use.
*
diff --git a/libavutil/version.h b/libavutil/version.h
index 3f82a97..16771ad 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -75,7 +75,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 52
-#define LIBAVUTIL_VERSION_MINOR 7
+#define LIBAVUTIL_VERSION_MINOR 8
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
diff --git a/tests/ref/fate/bprint b/tests/ref/fate/bprint
index e027fa1..b33c1ae 100644
--- a/tests/ref/fate/bprint
+++ b/tests/ref/fate/bprint
@@ -12,3 +12,5 @@ Short text in automatic buffer: 174/174
Long text in automatic buffer: 1000/2834
Long text count only buffer: 0/2834
Long text count only buffer: 255/2834
+strftime full: 255/10 "2000-12-20"
+strftime truncated: 255/10 "2000-12"
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