[FFmpeg-devel] [PATCH 1/1] librtmp: use AVBPrint instead of char *

[Tristan Matthews]

This avoids having to do one pass to calculate the full length to allocate
followed by a second pass to actually append values.
---
 libavformat/librtmp.c | 123 +++++++++++-------------------------------
 1 file changed, 32 insertions(+), 91 deletions(-)

diff --git a/libavformat/librtmp.c b/libavformat/librtmp.c
index 43013e46e0..7b379e48ee 100644
--- a/libavformat/librtmp.c
+++ b/libavformat/librtmp.c
@@ -25,6 +25,7 @@
  */
 
 #include "libavutil/avstring.h"
+#include "libavutil/bprint.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 #include "avformat.h"
@@ -50,7 +51,6 @@ typedef struct LibRTMPContext {
     char *pageurl;
     char *client_buffer_time;
     int live;
-    char *temp_filename;
     int buffer_size;
 } LibRTMPContext;
 
@@ -76,7 +76,6 @@ static int rtmp_close(URLContext *s)
     RTMP *r = &ctx->rtmp;
 
     RTMP_Close(r);
-    av_freep(&ctx->temp_filename);
     return 0;
 }
 
@@ -94,11 +93,11 @@ static int rtmp_close(URLContext *s)
  */
 static int rtmp_open(URLContext *s, const char *uri, int flags)
 {
+    AVBPrint filename;
     LibRTMPContext *ctx = s->priv_data;
     RTMP *r = &ctx->rtmp;
     int rc = 0, level;
-    char *filename = s->filename;
-    int len = strlen(s->filename) + 1;
+    av_bprint_init(&filename, 0, AV_BPRINT_SIZE_UNLIMITED);
 
     switch (av_log_get_level()) {
     default:
@@ -112,118 +111,58 @@ static int rtmp_open(URLContext *s, const char *uri, int flags)
     RTMP_LogSetLevel(level);
     RTMP_LogSetCallback(rtmp_log);
 
-    if (ctx->app)      len += strlen(ctx->app)      + sizeof(" app=");
-    if (ctx->tcurl)    len += strlen(ctx->tcurl)    + sizeof(" tcUrl=");
-    if (ctx->pageurl)  len += strlen(ctx->pageurl)  + sizeof(" pageUrl=");
-    if (ctx->flashver) len += strlen(ctx->flashver) + sizeof(" flashver=");
-
+    av_bprintf(&filename, "%s", s->filename);
+    if (ctx->app)
+        av_bprintf(&filename, " app=%s", ctx->app);
+    if (ctx->tcurl)
+        av_bprintf(&filename, " tcUrl=%s", ctx->tcurl);
+    if (ctx->pageurl)
+        av_bprintf(&filename, " pageUrl=%s", ctx->pageurl);
+    if (ctx->swfurl)
+        av_bprintf(&filename, " swfUrl=%s", ctx->swfurl);
+    if (ctx->flashver)
+        av_bprintf(&filename, " flashVer=%s", ctx->flashver);
     if (ctx->conn) {
         char *sep, *p = ctx->conn;
-        int options = 0;
-
         while (p) {
-            options++;
+            av_bprintf(&filename,  " conn=");
             p += strspn(p, " ");
             if (!*p)
                 break;
             sep = strchr(p, ' ');
+            if (sep)
+                *sep = '\0';
+            av_bprintf(&filename, "%s", p);
+
             if (sep)
                 p = sep + 1;
             else
                 break;
         }
-        len += options * sizeof(" conn=");
-        len += strlen(ctx->conn);
     }
-
     if (ctx->playpath)
-        len += strlen(ctx->playpath) + sizeof(" playpath=");
+        av_bprintf(&filename, " playpath=%s", ctx->playpath);
     if (ctx->live)
-        len += sizeof(" live=1");
+        av_bprintf(&filename, " live=1");
     if (ctx->subscribe)
-        len += strlen(ctx->subscribe) + sizeof(" subscribe=");
-
+        av_bprintf(&filename, " subscribe=%s", ctx->subscribe);
     if (ctx->client_buffer_time)
-        len += strlen(ctx->client_buffer_time) + sizeof(" buffer=");
-
+        av_bprintf(&filename, " buffer=%s", ctx->client_buffer_time);
     if (ctx->swfurl || ctx->swfverify) {
-        len += sizeof(" swfUrl=");
-
         if (ctx->swfverify)
-            len += strlen(ctx->swfverify) + sizeof(" swfVfy=1");
+            av_bprintf(&filename, " swfUrl=%s swfVfy=1", ctx->swfverify);
         else
-            len += strlen(ctx->swfurl);
+            av_bprintf(&filename, " swfUrl=%s", ctx->swfurl);
     }
 
-    if (!(ctx->temp_filename = filename = av_malloc(len)))
+    if (!av_bprint_is_complete(&filename)) {
+        av_bprint_finalize(&filename, NULL);
         return AVERROR(ENOMEM);
-
-    av_strlcpy(filename, s->filename, len);
-    if (ctx->app) {
-        av_strlcat(filename, " app=", len);
-        av_strlcat(filename, ctx->app, len);
-    }
-    if (ctx->tcurl) {
-        av_strlcat(filename, " tcUrl=", len);
-        av_strlcat(filename, ctx->tcurl, len);
-    }
-    if (ctx->pageurl) {
-        av_strlcat(filename, " pageUrl=", len);
-        av_strlcat(filename, ctx->pageurl, len);
-    }
-    if (ctx->swfurl) {
-        av_strlcat(filename, " swfUrl=", len);
-        av_strlcat(filename, ctx->swfurl, len);
-    }
-    if (ctx->flashver) {
-        av_strlcat(filename, " flashVer=", len);
-        av_strlcat(filename, ctx->flashver, len);
-    }
-    if (ctx->conn) {
-        char *sep, *p = ctx->conn;
-        while (p) {
-            av_strlcat(filename, " conn=", len);
-            p += strspn(p, " ");
-            if (!*p)
-                break;
-            sep = strchr(p, ' ');
-            if (sep)
-                *sep = '\0';
-            av_strlcat(filename, p, len);
-
-            if (sep)
-                p = sep + 1;
-            else
-                break;
-        }
-    }
-    if (ctx->playpath) {
-        av_strlcat(filename, " playpath=", len);
-        av_strlcat(filename, ctx->playpath, len);
-    }
-    if (ctx->live)
-        av_strlcat(filename, " live=1", len);
-    if (ctx->subscribe) {
-        av_strlcat(filename, " subscribe=", len);
-        av_strlcat(filename, ctx->subscribe, len);
-    }
-    if (ctx->client_buffer_time) {
-        av_strlcat(filename, " buffer=", len);
-        av_strlcat(filename, ctx->client_buffer_time, len);
-    }
-    if (ctx->swfurl || ctx->swfverify) {
-        av_strlcat(filename, " swfUrl=", len);
-
-        if (ctx->swfverify) {
-            av_strlcat(filename, ctx->swfverify, len);
-            av_strlcat(filename, " swfVfy=1", len);
-        } else {
-            av_strlcat(filename, ctx->swfurl, len);
-        }
     }
 
     RTMP_Init(r);
-    if (!RTMP_SetupURL(r, filename)) {
+    /* This will modify filename by null terminating the URL portion */
+    if (!RTMP_SetupURL(r, filename.str)) {
         rc = AVERROR_UNKNOWN;
         goto fail;
     }
@@ -247,9 +186,11 @@ static int rtmp_open(URLContext *s, const char *uri, int flags)
 #endif
 
     s->is_streamed = 1;
+    av_bprint_finalize(&filename, NULL);
     return 0;
 fail:
-    av_freep(&ctx->temp_filename);
+    av_bprint_finalize(&filename, NULL);
+
     if (rc)
         RTMP_Close(r);
 
-- 
2.32.0