The use_cache method is no longer supported.

4 files changed, 13 insertions, 24 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 136300fb..273f2c52 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -16,6 +16,8 @@ Latest
 - Code that was executed with `exec` would be mis-attributed to the file that
   called it.  This is now fixed, closing `issue 380`_.
 
+- The ``use_cache`` method is no longer supported.
+
 .. 41 issues closed in 4.0 so far
 
 .. _issue 380: https://bitbucket.org/ned/coveragepy/issues/380/code-executed-by-exec-excluded-from
diff --git a/coverage/control.py b/coverage/control.py
index 91365e11..7fc11700 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -601,13 +601,10 @@ class Coverage(object):
         sys.stderr.write("Coverage.py warning: %s\n" % msg)
 
     def use_cache(self, usecache):
-        """Control the use of a data file (incorrectly called a cache).
-
-        `usecache` is true or false, whether to read and write data on disk.
-
-        """
+        """Obsolete method."""
         self._init()
-        self.data.usefile(usecache)
+        if not usecache:
+            self._warn("use_cache(False) is no longer supported.")
 
     def load(self):
         """Load previously-collected coverage data from the data file."""
diff --git a/coverage/data.py b/coverage/data.py
index a1ce582c..69e928e2 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -40,8 +40,6 @@ class CoverageData(object):
         self.collector = collector or 'unknown'
         self.debug = debug
 
-        self.use_file = True
-
         # Construct the filename that will be used for data file storage, if we
         # ever do any file storage.
         self.filename = basename or ".coverage"
@@ -76,16 +74,9 @@ class CoverageData(object):
         #       }
         self.plugins = {}
 
-    def usefile(self, use_file=True):
-        """Set whether or not to use a disk file for data."""
-        self.use_file = use_file
-
     def read(self):
         """Read coverage data from the coverage data file (if it exists)."""
-        if self.use_file:
-            self.lines, self.arcs, self.plugins = self._read_file(self.filename)
-        else:
-            self.lines, self.arcs, self.plugins = {}, {}, {}
+        self.lines, self.arcs, self.plugins = self._read_file(self.filename)
 
     def write(self, suffix=None):
         """Write the collected coverage data to a file.
@@ -96,17 +87,15 @@ class CoverageData(object):
         the suffix.
 
         """
-        if self.use_file:
-            filename = self.filename
-            if suffix:
-                filename += "." + suffix
-            self.write_file(filename)
+        filename = self.filename
+        if suffix:
+            filename += "." + suffix
+        self.write_file(filename)
 
     def erase(self):
         """Erase the data, both in this object, and from its file storage."""
-        if self.use_file:
-            if self.filename:
-                file_be_gone(self.filename)
+        if self.filename:
+            file_be_gone(self.filename)
         self.lines = {}
         self.arcs = {}
         self.plugins = {}
diff --git a/doc/api.rst b/doc/api.rst
index 815b75e0..7c6dda35 100644
--- a/doc/api.rst
+++ b/doc/api.rst
@@ -37,6 +37,7 @@ The coverage module
 
 .. autoclass:: Coverage
     :members:
+    :exclude-members: use_cache
 
 
 Starting coverage automatically