adb: tracing: don't make strings if runtime tracing is disabled

If tracing was not enabled (the ADB_TRACE environment variable was not
set specially), writex() and readx() would still call dump_hex() which
would construct hex tracing strings, which would be immediately
discarded and not printed (because tracing is not enabled).

The fix is to only call dump_hex() if ADB_TRACING evalutes to true, the
same way that dump_packet() is only called if ADB_TRACING evaluates to
true.

Change-Id: I1651680da344389475ebdeea77ba1982960d5764
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/adb/transport.c b/adb/transport.c
index 7db6a47..ffe59da 100644
--- a/adb/transport.c
+++ b/adb/transport.c
@@ -1165,7 +1165,9 @@ int readx(int fd, void *ptr, size_t len)
 
 #if ADB_TRACE
     D("readx: fd=%d wanted=%zu got=%zu\n", fd, len0, len0 - len);
-    dump_hex( ptr, len0 );
+    if (ADB_TRACING) {
+        dump_hex( ptr, len0 );
+    }
 #endif
     return 0;
 }
@@ -1177,7 +1179,9 @@ int writex(int fd, const void *ptr, size_t len)
 
 #if ADB_TRACE
     D("writex: fd=%d len=%d: ", fd, (int)len);
-    dump_hex( ptr, len );
+    if (ADB_TRACING) {
+        dump_hex( ptr, len );
+    }
 #endif
     while(len > 0) {
         r = adb_write(fd, p, len);