librtmp: use AVBPrint instead of char *

This avoids having to do one pass to calculate the full length to allocate
followed by a second pass to actually append values.

Signed-off-by: Martin Storsjö <martin@martin.st>

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"
@@ -38,6 +39,7 @@
 
 typedef struct LibRTMPContext {
     const AVClass *class;
+    AVBPrint filename;
     RTMP rtmp;
     char *app;
     char *conn;
@@ -50,7 +52,6 @@ typedef struct LibRTMPContext {
     char *pageurl;
     char *client_buffer_time;
     int live;
-    char *temp_filename;
     int buffer_size;
 } LibRTMPContext;
 
@@ -76,7 +77,7 @@ static int rtmp_close(URLContext *s)
     RTMP *r = &ctx->rtmp;
 
     RTMP_Close(r);
-    av_freep(&ctx->temp_filename);
+    av_bprint_finalize(&ctx->filename, NULL);
     return 0;
 }
 
@@ -97,8 +98,8 @@ static int rtmp_open(URLContext *s, const char *uri, int flags)
     LibRTMPContext *ctx = s->priv_data;
     RTMP *r = &ctx->rtmp;
     int rc = 0, level;
-    char *filename = s->filename;
+    /* This needs to stay allocated for as long as the RTMP context exists. */
-    int len = strlen(s->filename) + 1;
+    av_bprint_init(&ctx->filename, 0, AV_BPRINT_SIZE_UNLIMITED);
 
     switch (av_log_get_level()) {
     default:
@@ -112,84 +113,28 @@ 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=");
+    av_bprintf(&ctx->filename, "%s", s->filename);
-    if (ctx->tcurl)    len += strlen(ctx->tcurl)    + sizeof(" tcUrl=");
+    if (ctx->app)
-    if (ctx->pageurl)  len += strlen(ctx->pageurl)  + sizeof(" pageUrl=");
+        av_bprintf(&ctx->filename, " app=%s", ctx->app);
-    if (ctx->flashver) len += strlen(ctx->flashver) + sizeof(" flashver=");
+    if (ctx->tcurl)
-
+        av_bprintf(&ctx->filename, " tcUrl=%s", ctx->tcurl);
-    if (ctx->conn) {
+    if (ctx->pageurl)
-        char *sep, *p = ctx->conn;
+        av_bprintf(&ctx->filename, " pageUrl=%s", ctx->pageurl);
-        int options = 0;
+    if (ctx->swfurl)
-
+        av_bprintf(&ctx->filename, " swfUrl=%s", ctx->swfurl);
-        while (p) {
+    if (ctx->flashver)
-            options++;
+        av_bprintf(&ctx->filename, " flashVer=%s", ctx->flashver);
-            p += strspn(p, " ");
-            if (!*p)
-                break;
-            sep = strchr(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=");
-    if (ctx->live)
-        len += sizeof(" live=1");
-    if (ctx->subscribe)
-        len += strlen(ctx->subscribe) + sizeof(" subscribe=");
-
-    if (ctx->client_buffer_time)
-        len += strlen(ctx->client_buffer_time) + sizeof(" buffer=");
-
-    if (ctx->swfurl || ctx->swfverify) {
-        len += sizeof(" swfUrl=");
-
-        if (ctx->swfverify)
-            len += strlen(ctx->swfverify) + sizeof(" swfVfy=1");
-        else
-            len += strlen(ctx->swfurl);
-    }
-
-    if (!(ctx->temp_filename = filename = av_malloc(len)))
-        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);
+            av_bprintf(&ctx->filename,  " conn=");
             p += strspn(p, " ");
             if (!*p)
                 break;
             sep = strchr(p, ' ');
             if (sep)
                 *sep = '\0';
-            av_strlcat(filename, p, len);
+            av_bprintf(&ctx->filename, "%s", p);
 
             if (sep)
                 p = sep + 1;
@@ -197,33 +142,29 @@ static int rtmp_open(URLContext *s, const char *uri, int flags)
                 break;
         }
     }
-    if (ctx->playpath) {
+    if (ctx->playpath)
-        av_strlcat(filename, " playpath=", len);
+        av_bprintf(&ctx->filename, " playpath=%s", ctx->playpath);
-        av_strlcat(filename, ctx->playpath, len);
-    }
     if (ctx->live)
-        av_strlcat(filename, " live=1", len);
+        av_bprintf(&ctx->filename, " live=1");
-    if (ctx->subscribe) {
+    if (ctx->subscribe)
-        av_strlcat(filename, " subscribe=", len);
+        av_bprintf(&ctx->filename, " subscribe=%s", ctx->subscribe);
-        av_strlcat(filename, ctx->subscribe, len);
+    if (ctx->client_buffer_time)
-    }
+        av_bprintf(&ctx->filename, " buffer=%s", ctx->client_buffer_time);
-    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_bprintf(&ctx->filename, " swfUrl=%s swfVfy=1", ctx->swfverify);
-        if (ctx->swfverify) {
+        else
-            av_strlcat(filename, ctx->swfverify, len);
+            av_bprintf(&ctx->filename, " swfUrl=%s", ctx->swfurl);
-            av_strlcat(filename, " swfVfy=1", len);
-        } else {
-            av_strlcat(filename, ctx->swfurl, len);
     }
+
+    if (!av_bprint_is_complete(&ctx->filename)) {
+        av_bprint_finalize(&ctx->filename, NULL);
+        return AVERROR(ENOMEM);
     }
 
     RTMP_Init(r);
-    if (!RTMP_SetupURL(r, filename)) {
+    /* This will modify filename by null terminating the URL portion */
+    if (!RTMP_SetupURL(r, ctx->filename.str)) {
         rc = AVERROR_UNKNOWN;
         goto fail;
     }
@@ -249,9 +190,10 @@ static int rtmp_open(URLContext *s, const char *uri, int flags)
     s->is_streamed = 1;
     return 0;
 fail:
-    av_freep(&ctx->temp_filename);
+
     if (rc)
         RTMP_Close(r);
+    av_bprint_finalize(&ctx->filename, NULL);
 
     return rc;
 }