tools/patch_from_svn can generate diff from a SVN directory directly

Change-Id: I3abc602627575901d75fde42f73d73675522ee2a

tools/patch_from_svn

 #!/bin/bash
 if [ -z "$1" ]; then
-    echo "Usage: patch_from_svn some.patch"
-    echo "The patch should be generated by 'svn diff -c <REV>'"
+    echo "Usage1: patch_from_svn PATCHFILE (generated by 'svn diff -c REVISION')"
+    echo "Usage2: patch_from_svn SVN_DIR REVISION"
     exit 1
 fi
-cat $1 |sed -e 's/src\/baidu\/rpc\//brpc\//g' \
+PATCHFILE=$1
+if [ -d "$1/.svn" ]; then
+    if [ -z "$2" ]; then
+        echo "Second argument must be a SVN revision"
+        exit 1
+    fi
+    SVN_DIR=$1
+    REV=$2
+    PATCHFILE=$REV.patch
+    echo "*** Generating diff of $SVN_DIR@$REV"
+    svn diff $SVN_DIR -c $REV > $PATCHFILE
+fi
+
+MODIFIED_PATCHFILE="$(basename $PATCHFILE).brpc_os"
+
+cat $PATCHFILE | sed -e 's/src\/baidu\/rpc\//brpc\//g' \
             -e 's/\<baidu\/rpc\//brpc\//g' \
             -e 's/brpc\/test\/test_\(.*\)\.cpp/test\/brpc_\1_unittest.cpp/g' \
             -e 's/\<namespace \+baidu *{/namespace brpc {/g' \
@@ -26,10 +41,11 @@ cat $1 |sed -e 's/src\/baidu\/rpc\//brpc\//g' \
             -e 's/<\(base\/[^>]*\)>/"\1"/g' \
             -e 's/<\(bthread\/[^>]*\)>/"\1"/g' \
             -e 's/<\(mcpack2pb\/[^>]*\)>/"\1"/g' \
-            > $1.brpc_os
+            > $MODIFIED_PATCHFILE
 EXTRA_ARGS=
 if [ -z "$DO_RUN" ]; then
     EXTRA_ARGS="--dry-run $EXTRA_ARGS"
     echo "*** This is a dry-run. To really apply, run: DO_RUN=1 tools/patch_from_svn $1"
 fi
-patch -p0 -u $EXTRA_ARGS < $1.brpc_os
+patch -p0 -u $EXTRA_ARGS < $MODIFIED_PATCHFILE
+rm $MODIFIED_PATCHFILE