Save target_metrics into state file

dvc/git_wrapper.py

@@ -2,6 +2,7 @@ import os
 import re
 from collections import defaultdict
 
+from dvc.exceptions import DvcException
 from dvc.logger import Logger
 from dvc.config import Config
 from dvc.executor import Executor, ExecutorError
@@ -11,6 +12,11 @@ from dvc.graph.workflow import Workflow
 from dvc.graph.commit import Commit
 
 
+class GitWrapperError(DvcException):
+    def __init__(self, msg):
+        DvcException.__init__(self, msg)
+
+
 class GitWrapperI(object):
     COMMIT_LEN = 7
 
@@ -325,21 +331,33 @@ class GitWrapper(GitWrapperI):
         if not os.path.exists(full_file_name):
             return None
 
-        lines = open(full_file_name).readlines(2)
-        if len(lines) != 1:
-            msg = '[dvc-git] Target file {} with hash {} has wrong format: {} lines were obtained, 1 expected.'
-            Logger.warn(msg.format(target, hash, len(lines)))
+        try:
+            return self.parse_target_metric(full_file_name)
+        except GitWrapperError as ex:
+            msg = '[dvc-git] Unable to parse target file {} from Git commit {}: {}'
+            Logger.warn(msg.format(target, hash, ex))
             return None
 
+    @staticmethod
+    def parse_target_metric(file_name):
+        lines = open(file_name).readlines(2)
+        if len(lines) != 1:
+            raise GitWrapperError('file contains more then one line')
+
         # Extract float from string. I.e. from 'AUC: 0.596182'
-        nums = self.FLOATS_FROM_STRING.findall(lines[0])
+        nums = GitWrapper.FLOATS_FROM_STRING.findall(lines[0])
         if len(nums) < 1:
-            msg = '[dvc-git] Unable to parse metrics from \'{}\' file {}'
-            Logger.warn(msg.format(lines[0], target))
-            return None
+            raise GitWrapperError("Unable to parse metrics from the first line")
 
         return float(nums[0])
 
+    @staticmethod
+    def try_parse_target_metric(file_name):
+        try:
+            return GitWrapper.parse_target_metric(file_name)
+        except GitWrapperError:
+            return None
+
     @staticmethod
     def get_merges_map():
         # git log --merges --all --abbrev=7

dvc/state_file.py

@@ -5,6 +5,7 @@ import json
 import time
 
 from dvc.exceptions import DvcException
+from dvc.git_wrapper import GitWrapper
 from dvc.path.data_item import NotInDataDirError
 from dvc.system import System
 
@@ -39,6 +40,8 @@ class StateFile(object):
     PARAM_STDOUT = "Stdout"
     PARAM_STDERR = "Stderr"
     PARAM_SHELL = "Shell"
+    PARAM_TARGET_METRICS = 'target_metrics'
+    TARGET_METRICS_SINGLE_METRIC = 'single_metric'
 
     def __init__(self,
                  command,
@@ -55,7 +58,7 @@ class StateFile(object):
                  cwd=None,
                  shell=False):
         self.data_item = data_item
-        self.file = data_item.state.relative
+        self.file = self.data_item.state.relative
         self.settings = settings
         self.input_files = input_files
         self.output_files = output_files
@@ -78,7 +81,12 @@ class StateFile(object):
             self.cwd = cwd
         else:
             self.cwd = self.get_dvc_path()
-        pass
+
+        self.target_metrics = {}
+
+        target_metric = GitWrapper.try_parse_target_metric(self.data_item.data.relative)
+        if target_metric:
+            self.target_metrics[StateFile.TARGET_METRICS_SINGLE_METRIC] = target_metric
 
     @property
     def is_import_file(self):
@@ -158,6 +166,7 @@ class StateFile(object):
             self.PARAM_STDOUT:              self.encode_path(self.stdout),
             self.PARAM_STDERR:              self.encode_path(self.stderr),
             self.PARAM_SHELL:               self.shell,
+            self.PARAM_TARGET_METRICS:      self.target_metrics
         }
 
         if self.locked: