From 43f42cbb4cf68c01075ec4df72211e3285cb2992 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mike.jumper@guac-dev.org>
Date: Fri, 5 Apr 2013 13:15:19 -0700
Subject: [PATCH] Use pre-allocated scratch area, rather than
 constantly-reallocated scratch area.

---
 protocols/ssh/include/terminal.h |  6 ++++++
 protocols/ssh/src/terminal.c     | 12 +++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/protocols/ssh/include/terminal.h b/protocols/ssh/include/terminal.h
index 2b831f40..1f07ee49 100644
--- a/protocols/ssh/include/terminal.h
+++ b/protocols/ssh/include/terminal.h
@@ -195,6 +195,12 @@ typedef struct guac_terminal_delta {
      */
     guac_terminal_operation* operations;
 
+    /**
+     * Scratch area of same size as the operations buffer, facilitating copies
+     * of overlapping regions.
+     */
+    guac_terminal_operation* scratch;
+
     /**
      * The width of the screen, in characters.
      */
diff --git a/protocols/ssh/src/terminal.c b/protocols/ssh/src/terminal.c
index 656c05bf..40d72cfa 100644
--- a/protocols/ssh/src/terminal.c
+++ b/protocols/ssh/src/terminal.c
@@ -580,14 +580,18 @@ guac_terminal_delta* guac_terminal_delta_alloc(int width, int height) {
 
     }
 
+    /* Alloc scratch area */
+    delta->scratch = malloc(width * height * sizeof(guac_terminal_operation));
+
     return delta;
 
 }
 
 void guac_terminal_delta_free(guac_terminal_delta* delta) {
 
-    /* Free operations buffer */
+    /* Free operations buffers */
     free(delta->operations);
+    free(delta->scratch);
 
     /* Free delta */
     free(delta);
@@ -620,16 +624,14 @@ void guac_terminal_delta_copy(guac_terminal_delta* delta,
 
     /* FIXME: Handle intersections between src and dst rects */
 
-    guac_terminal_operation* src_copy = malloc(
-            sizeof(guac_terminal_operation) * delta->width * delta->height);
-    memcpy(src_copy, delta->operations, 
+    memcpy(delta->scratch, delta->operations, 
             sizeof(guac_terminal_operation) * delta->width * delta->height);
 
     guac_terminal_operation* current_row =
         &(delta->operations[dst_row*delta->width + dst_column]);
 
     guac_terminal_operation* src_current_row =
-        &(src_copy[src_row*delta->width + src_column]);
+        &(delta->scratch[src_row*delta->width + src_column]);
 
     /* Set rectangle to copy operations */
     for (row=0; row<h; row++) {