Add python coverage module to third_party

third_party/pycoverage/coverage/data.py

Index: third_party/pycoverage/coverage/data.py
diff --git a/third_party/pycoverage/coverage/data.py b/third_party/pycoverage/coverage/data.py
new file mode 100644
index 0000000000000000000000000000000000000000..fb88c5b1e638cdd5954c3818a08d000a4ec499eb
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+++ b/third_party/pycoverage/coverage/data.py
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+"""Coverage data for Coverage."""
+
+import os
+
+from coverage.backward import iitems, pickle, sorted    # pylint: disable=W0622
+from coverage.files import PathAliases
+from coverage.misc import file_be_gone
+
+
+class CoverageData(object):
+    """Manages collected coverage data, including file storage.
+
+    The data file format is a pickled dict, with these keys:
+
+        * collector: a string identifying the collecting software
+
+        * lines: a dict mapping filenames to sorted lists of line numbers
+          executed:
+            { 'file1': [17,23,45],  'file2': [1,2,3], ... }
+
+        * arcs: a dict mapping filenames to sorted lists of line number pairs:
+            { 'file1': [(17,23), (17,25), (25,26)], ... }
+
+    """
+
+    def __init__(self, basename=None, collector=None, debug=None):
+        """Create a CoverageData.
+
+        `basename` is the name of the file to use for storing data.
+
+        `collector` is a string describing the coverage measurement software.
+
+        `debug` is a `DebugControl` object for writing debug messages.
+
+        """
+        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"
+        self.filename = os.path.abspath(self.filename)
+
+        # A map from canonical Python source file name to a dictionary in
+        # which there's an entry for each line number that has been
+        # executed:
+        #
+        #   {
+        #       'filename1.py': { 12: None, 47: None, ... },
+        #       ...
+        #       }
+        #
+        self.lines = {}
+
+        # A map from canonical Python source file name to a dictionary with an
+        # entry for each pair of line numbers forming an arc:
+        #
+        #   {
+        #       'filename1.py': { (12,14): None, (47,48): None, ... },
+        #       ...
+        #       }
+        #
+        self.arcs = {}
+
+    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._read_file(self.filename)
+        else:
+            self.lines, self.arcs = {}, {}
+
+    def write(self, suffix=None):
+        """Write the collected coverage data to a file.
+
+        `suffix` is a suffix to append to the base file name. This can be used
+        for multiple or parallel execution, so that many coverage data files
+        can exist simultaneously.  A dot will be used to join the base name and
+        the suffix.
+
+        """
+        if self.use_file:
+            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)
+        self.lines = {}
+        self.arcs = {}
+
+    def line_data(self):
+        """Return the map from filenames to lists of line numbers executed."""
+        return dict(
+            [(f, sorted(lmap.keys())) for f, lmap in iitems(self.lines)]
+            )
+
+    def arc_data(self):
+        """Return the map from filenames to lists of line number pairs."""
+        return dict(
+            [(f, sorted(amap.keys())) for f, amap in iitems(self.arcs)]
+            )
+
+    def write_file(self, filename):
+        """Write the coverage data to `filename`."""
+
+        # Create the file data.
+        data = {}
+
+        data['lines'] = self.line_data()
+        arcs = self.arc_data()
+        if arcs:
+            data['arcs'] = arcs
+
+        if self.collector:
+            data['collector'] = self.collector
+
+        if self.debug and self.debug.should('dataio'):
+            self.debug.write("Writing data to %r" % (filename,))
+
+        # Write the pickle to the file.
+        fdata = open(filename, 'wb')
+        try:
+            pickle.dump(data, fdata, 2)
+        finally:
+            fdata.close()
+
+    def read_file(self, filename):
+        """Read the coverage data from `filename`."""
+        self.lines, self.arcs = self._read_file(filename)
+
+    def raw_data(self, filename):
+        """Return the raw pickled data from `filename`."""
+        if self.debug and self.debug.should('dataio'):
+            self.debug.write("Reading data from %r" % (filename,))
+        fdata = open(filename, 'rb')
+        try:
+            data = pickle.load(fdata)
+        finally:
+            fdata.close()
+        return data
+
+    def _read_file(self, filename):
+        """Return the stored coverage data from the given file.
+
+        Returns two values, suitable for assigning to `self.lines` and
+        `self.arcs`.
+
+        """
+        lines = {}
+        arcs = {}
+        try:
+            data = self.raw_data(filename)
+            if isinstance(data, dict):
+                # Unpack the 'lines' item.
+                lines = dict([
+                    (f, dict.fromkeys(linenos, None))
+                        for f, linenos in iitems(data.get('lines', {}))
+                    ])
+                # Unpack the 'arcs' item.
+                arcs = dict([
+                    (f, dict.fromkeys(arcpairs, None))
+                        for f, arcpairs in iitems(data.get('arcs', {}))
+                    ])
+        except Exception:
+            pass
+        return lines, arcs
+
+    def combine_parallel_data(self, aliases=None):
+        """Combine a number of data files together.
+
+        Treat `self.filename` as a file prefix, and combine the data from all
+        of the data files starting with that prefix plus a dot.
+
+        If `aliases` is provided, it's a `PathAliases` object that is used to
+        re-map paths to match the local machine's.
+
+        """
+        aliases = aliases or PathAliases()
+        data_dir, local = os.path.split(self.filename)
+        localdot = local + '.'
+        for f in os.listdir(data_dir or '.'):
+            if f.startswith(localdot):
+                full_path = os.path.join(data_dir, f)
+                new_lines, new_arcs = self._read_file(full_path)
+                for filename, file_data in iitems(new_lines):
+                    filename = aliases.map(filename)
+                    self.lines.setdefault(filename, {}).update(file_data)
+                for filename, file_data in iitems(new_arcs):
+                    filename = aliases.map(filename)
+                    self.arcs.setdefault(filename, {}).update(file_data)
+                if f != local:
+                    os.remove(full_path)
+
+    def add_line_data(self, line_data):
+        """Add executed line data.
+
+        `line_data` is { filename: { lineno: None, ... }, ...}
+
+        """
+        for filename, linenos in iitems(line_data):
+            self.lines.setdefault(filename, {}).update(linenos)
+
+    def add_arc_data(self, arc_data):
+        """Add measured arc data.
+
+        `arc_data` is { filename: { (l1,l2): None, ... }, ...}
+
+        """
+        for filename, arcs in iitems(arc_data):
+            self.arcs.setdefault(filename, {}).update(arcs)
+
+    def touch_file(self, filename):
+        """Ensure that `filename` appears in the data, empty if needed."""
+        self.lines.setdefault(filename, {})
+
+    def measured_files(self):
+        """A list of all files that had been measured."""
+        return list(self.lines.keys())
+
+    def executed_lines(self, filename):
+        """A map containing all the line numbers executed in `filename`.
+
+        If `filename` hasn't been collected at all (because it wasn't executed)
+        then return an empty map.
+
+        """
+        return self.lines.get(filename) or {}
+
+    def executed_arcs(self, filename):
+        """A map containing all the arcs executed in `filename`."""
+        return self.arcs.get(filename) or {}
+
+    def add_to_hash(self, filename, hasher):
+        """Contribute `filename`'s data to the Md5Hash `hasher`."""
+        hasher.update(self.executed_lines(filename))
+        hasher.update(self.executed_arcs(filename))
+
+    def summary(self, fullpath=False):
+        """Return a dict summarizing the coverage data.
+
+        Keys are based on the filenames, and values are the number of executed
+        lines.  If `fullpath` is true, then the keys are the full pathnames of
+        the files, otherwise they are the basenames of the files.
+
+        """
+        summ = {}
+        if fullpath:
+            filename_fn = lambda f: f
+        else:
+            filename_fn = os.path.basename
+        for filename, lines in iitems(self.lines):
+            summ[filename_fn(filename)] = len(lines)
+        return summ
+
+    def has_arcs(self):
+        """Does this data have arcs?"""
+        return bool(self.arcs)
+
+
+if __name__ == '__main__':
+    # Ad-hoc: show the raw data in a data file.
+    import pprint, sys
+    covdata = CoverageData()
+    if sys.argv[1:]:
+        fname = sys.argv[1]
+    else:
+        fname = covdata.filename
+    pprint.pprint(covdata.raw_data(fname))