changeset 23368:bf8c3172255c

vfs: add "readlines" and "tryreadlines"

This patch allows "readlines" and "tryreadlines" to take "mode"
argument, because "subrepo" requires to read files not in "rb"
(binary, default for vfs) but in "r" (text) mode in subsequent patch.

--- a/mercurial/scmutil.py	Wed Nov 19 18:35:14 2014 +0900
+++ b/mercurial/scmutil.py	Wed Nov 19 18:35:14 2014 +0900
@@ -188,6 +188,15 @@
                 raise
         return ""
 
+    def tryreadlines(self, path, mode='rb'):
+        '''gracefully return an empty array for missing files'''
+        try:
+            return self.readlines(path, mode=mode)
+        except IOError, inst:
+            if inst.errno != errno.ENOENT:
+                raise
+        return []
+
     def open(self, path, mode="r", text=False, atomictemp=False):
         self.open = self.__call__
         return self.__call__(path, mode, text, atomictemp)
@@ -199,6 +208,13 @@
         finally:
             fp.close()
 
+    def readlines(self, path, mode='rb'):
+        fp = self(path, mode=mode)
+        try:
+            return fp.readlines()
+        finally:
+            fp.close()
+
     def write(self, path, data):
         fp = self(path, 'wb')
         try: