Change growth function for SkWriter32

src/core/SkWriter32.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkReader32.h"
 #include "SkString.h"
 #include "SkWriter32.h"
@@ skipping 49 matching lines @@
 size_t SkWriter32::WriteStringSize(const char* str, size_t len) {
     if ((long)len < 0) {
         SkASSERT(str);
         len = strlen(str);
     }
     const size_t lenBytes = 4;    // we use 4 bytes to record the length
     // add 1 since we also write a terminating 0
     return SkAlign4(lenBytes + len + 1);
 }
 
+const size_t kMinBufferBytes=4096;
+
 void SkWriter32::growToAtLeast(size_t size) {
     bool wasExternal = (fExternal != NULL) && (fData == fExternal);
+    fCapacity = kMinBufferBytes +
+        SkTMax(size, fCapacity + (fCapacity >> 1));
+
     // cause the buffer to grow
-    fInternal.setCount(size);
+    fInternal.setCountExact(fCapacity);
+    SkASSERT(fInternal.count() == (int)fCapacity);
+    // read back the capacity in case it was already larger than this
+    fCapacity = fInternal.reserved();
     fData = fInternal.begin();
     if (wasExternal) {
         // we were external, so copy in the data
         memcpy(fData, fExternal, fUsed);
     }
-    // Find out the size the buffer grew to, it may be more than we asked for.
-    fCapacity = fInternal.reserved();
-    // Expand the array so all reserved space is "used", we maintain the
-    // amount we have written manually outside the array
-    fInternal.setCount(fCapacity);
-    SkASSERT(fInternal.count() == (int)fCapacity);
     SkASSERT(fInternal.reserved() == (int)fCapacity);
 }