Add dvc run --deterministic option.

dvc/cli.py

@@ -268,9 +268,28 @@ def parse_args(argv=None):
                         '--yes',
                         action='store_true',
                         default=False,
-                        help="Automatic 'yes' answer to all prompts. E.g. "
+                        help="(OBSOLETED, use --overwrite-dvcfile instead) "
+                             "Automatic 'yes' answer to all prompts. E.g. "
                              "when '.dvc' file exists and dvc asks if you "
                              "want to overwrite it.")
+    run_parser.add_argument(
+                        '--overwrite-dvcfile',
+                        action='store_true',
+                        default=False,
+                        help="Overwrite existing dvc file without asking "
+                             "for confirmation.")
+    run_parser.add_argument(
+                        '--ignore-build-cache',
+                        action='store_true',
+                        default=False,
+                        help="Run this stage even if it has been already "
+                        "ran with the same command/dependencies/outputs/etc "
+                        "before.")
+    run_parser.add_argument(
+                        '--remove-outs',
+                        action='store_true',
+                        default=False,
+                        help="Remove outputs before running the command.")
     run_parser.add_argument(
                         'command',
                         nargs=argparse.REMAINDER,

dvc/command/run.py

@@ -20,18 +20,19 @@ def _joined_cmd(self):
         return cmd
 
     def run(self):
+        overwrite = (self.args.yes or self.args.overwrite_dvcfile)
         try:
-            if self.args.yes:
-                self.project.prompt.default = True
-
             self.project.run(cmd=self._joined_cmd(),
                              outs=self.args.outs,
                              outs_no_cache=self.args.outs_no_cache,
                              metrics_no_cache=self.args.metrics_no_cache,
                              deps=self.args.deps,
                              fname=self.args.file,
                              cwd=self.args.cwd,
-                             no_exec=self.args.no_exec)
+                             no_exec=self.args.no_exec,
+                             overwrite=overwrite,
+                             ignore_build_cache=self.args.ignore_build_cache,
+                             remove_outs=self.args.remove_outs)
         except DvcException as ex:
             self.project.logger.error('Failed to run command', ex)
             return 1

dvc/project.py

@@ -325,16 +325,21 @@ def move(self, from_path, to_path):
     def _unprotect_file(self, path):
         import stat
         import uuid
+        from dvc.system import System
         from dvc.utils import copyfile, move, remove
 
-        self.logger.debug("Unprotecting '{}'".format(path))
+        if System.is_symlink(path) or System.is_hardlink(path):
+            self.logger.debug("Unprotecting '{}'".format(path))
 
-        tmp = os.path.join(os.path.dirname(path), '.' + str(uuid.uuid4()))
-        move(path, tmp)
+            tmp = os.path.join(os.path.dirname(path), '.' + str(uuid.uuid4()))
+            move(path, tmp)
 
-        copyfile(tmp, path)
+            copyfile(tmp, path)
 
-        remove(tmp)
+            remove(tmp)
+        else:
+            self.logger.debug("Skipping copying for '{}', since it is not "
+                              "a symlink or a hardlink.".format(path))
 
         os.chmod(path, os.stat(path).st_mode | stat.S_IWRITE)
 
@@ -363,18 +368,26 @@ def run(self,
             fname=None,
             cwd=os.curdir,
             no_exec=False,
-            overwrite=False):
+            overwrite=False,
+            ignore_build_cache=False,
+            remove_outs=False):
         from dvc.stage import Stage
 
-        stage = Stage.loads(project=self,
-                            fname=fname,
-                            cmd=cmd,
-                            cwd=cwd,
-                            outs=outs,
-                            outs_no_cache=outs_no_cache,
-                            metrics_no_cache=metrics_no_cache,
-                            deps=deps,
-                            overwrite=overwrite)
+        with self.state:
+            stage = Stage.loads(project=self,
+                                fname=fname,
+                                cmd=cmd,
+                                cwd=cwd,
+                                outs=outs,
+                                outs_no_cache=outs_no_cache,
+                                metrics_no_cache=metrics_no_cache,
+                                deps=deps,
+                                overwrite=overwrite,
+                                ignore_build_cache=ignore_build_cache,
+                                remove_outs=remove_outs)
+
+        if stage is None:
+            return None
 
         all_stages = self.stages()
 

dvc/stage.py

@@ -29,6 +29,12 @@ def __init__(self, fname):
         super(StageFileDoesNotExistError, self).__init__(msg)
 
 
+class StageFileAlreadyExistsError(DvcException):
+    def __init__(self, relpath):
+        msg = "Stage '{}' already exists".format(relpath)
+        super(StageFileAlreadyExistsError, self).__init__(msg)
+
+
 class StageFileIsNotDvcFileError(DvcException):
     def __init__(self, fname):
         msg = "'{}' is not a dvc file".format(fname)
@@ -149,7 +155,10 @@ def is_import(self):
                len(self.deps) == 1 and \
                len(self.outs) == 1
 
-    def _changed_deps(self, print_info, log):
+    def _changed_deps(self, log):
+        if self.locked:
+            return False
+
         if self.is_callback:
             msg = "Dvc file '{}' is a 'callback' stage (has a command and " \
                   "no dependencies) and thus always considered as changed."
@@ -159,37 +168,35 @@ def _changed_deps(self, print_info, log):
         for dep in self.deps:
             if not dep.changed():
                 continue
-            if print_info:
-                msg = "Dependency '{}' of '{}' changed."
-                log(msg.format(dep, self.relpath))
+            log("Dependency '{}' of '{}' changed.".format(dep, self.relpath))
             return True
 
         return False
 
-    def changed(self, print_info=False):
-        ret = False
+    def _changed_outs(self, log):
+        for out in self.outs:
+            if not out.changed():
+                continue
+            log("Output '{}' of '{}' changed.".format(out, self.relpath))
+            return True
+
+        return False
+
+    def _changed_md5(self, log):
+        if self.changed_md5():
+            log("Dvc file '{}' changed.".format(self.relpath))
+            return True
+        return False
 
+    def changed(self, print_info=False):
         if print_info:
             log = self.project.logger.info
         else:
             log = self.project.logger.debug
 
-        if not self.locked:
-            ret = self._changed_deps(print_info, log)
-
-        for out in self.outs:
-            if not out.changed():
-                continue
-            if print_info:
-                msg = "Output '{}' of '{}' changed."
-                log(msg.format(out, self.relpath))
-            ret = True
-
-        if self.changed_md5():
-            if print_info:
-                msg = "Dvc file '{}' changed."
-                log(msg.format(self.relpath))
-            ret = True
+        ret = any([self._changed_deps(log),
+                   self._changed_outs(log),
+                   self._changed_md5(log)])
 
         if ret:
             msg = "Stage '{}' changed.".format(self.relpath)
@@ -206,6 +213,12 @@ def remove_outs(self, ignore_remove=False):
         for out in self.outs:
             out.remove(ignore_remove=ignore_remove)
 
+    def unprotect_outs(self):
+        for out in self.outs:
+            if out.path_info['scheme'] != 'local' or not out.exists:
+                continue
+            self.project.unprotect(out.path)
+
     def remove(self):
         self.remove_outs(ignore_remove=True)
         os.unlink(self.path)
@@ -290,6 +303,37 @@ def _check_inside_project(project, cwd):
         if not os.path.realpath(cwd).startswith(proj_dir):
             raise StageBadCwdError(cwd)
 
+    def is_cached(self):
+        """
+        Checks if this stage has been already ran and saved to the same
+        dvc file.
+        """
+        from dvc.remote.local import RemoteLOCAL
+        from dvc.remote.s3 import RemoteS3
+
+        old = Stage.load(self.project, self.path)
+        if old._changed_outs(log=self.project.logger.debug):
+            return False
+
+        # NOTE: need to save checksums for deps in order to compare them
+        # with what is written in the old stage.
+        for dep in self.deps:
+            dep.save()
+
+        old_d = old.dumpd()
+        new_d = self.dumpd()
+
+        # NOTE: need to remove checksums from old dict in order to compare
+        # it to the new one, since the new one doesn't have checksums yet.
+        old_d.pop(self.PARAM_MD5, None)
+        new_d.pop(self.PARAM_MD5, None)
+        outs = old_d.get(self.PARAM_OUTS, [])
+        for out in outs:
+            out.pop(RemoteLOCAL.PARAM_MD5, None)
+            out.pop(RemoteS3.PARAM_ETAG, None)
+
+        return old_d == new_d
+
     @staticmethod
     def loads(project=None,
               cmd=None,
@@ -301,7 +345,10 @@ def loads(project=None,
               cwd=os.curdir,
               locked=False,
               add=False,
-              overwrite=True):
+              overwrite=True,
+              ignore_build_cache=False,
+              remove_outs=False):
+
         stage = Stage(project=project,
                       cwd=cwd,
                       cmd=cmd,
@@ -325,17 +372,28 @@ def loads(project=None,
         cwd = os.path.abspath(cwd)
         path = os.path.join(cwd, fname)
 
-        if os.path.exists(path):
-            relpath = os.path.relpath(path)
-            msg = "'{}' already exists. " \
-                  "Do you wish to run the command and overwrite it?"
-            if not overwrite \
-               and not project.prompt.prompt(msg.format(relpath), False):
-                raise DvcException("'{}' already exists".format(relpath))
-
         stage.cwd = cwd
         stage.path = path
 
+        # NOTE: remove outs before we check build cache
+        if remove_outs:
+            stage.remove_outs(ignore_remove=False)
+            project.logger.warn("Build cache is ignored when using "
+                                "--remove-outs.")
+            ignore_build_cache = True
+        else:
+            stage.unprotect_outs()
+
+        if os.path.exists(path):
+            if not ignore_build_cache and stage.is_cached():
+                Logger.info('Stage is cached, skipping.')
+                return None
+
+            msg = "'{}' already exists. Do you wish to run the command and " \
+                  "overwrite it?".format(stage.relpath)
+            if not overwrite and not project.prompt.prompt(msg, False):
+                raise StageFileAlreadyExistsError(stage.relpath)
+
         return stage
 
     @staticmethod

dvc/system.py

@@ -127,6 +127,11 @@ def getdirinfo(path):
         from ctypes import c_void_p, c_wchar_p, Structure, WinError, POINTER
         from ctypes.wintypes import DWORD, HANDLE, BOOL
 
+        # NOTE: use this flag to open symlink itself and not the target
+        # See https://docs.microsoft.com/en-us/windows/desktop/api/
+        # fileapi/nf-fileapi-createfilew#symbolic-link-behavior
+        FILE_FLAG_OPEN_REPARSE_POINT = 0x00200000
+
         FILE_FLAG_BACKUP_SEMANTICS = 0x02000000
         FILE_SHARE_READ = 0x00000001
         OPEN_EXISTING = 3
@@ -147,7 +152,7 @@ class BY_HANDLE_FILE_INFORMATION(Structure):
                         ("nFileIndexHigh", DWORD),
                         ("nFileIndexLow", DWORD)]
 
-        flags = FILE_FLAG_BACKUP_SEMANTICS
+        flags = FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT
 
         func = ctypes.windll.kernel32.CreateFileW
         func.argtypes = [c_wchar_p,
@@ -240,3 +245,22 @@ def wait_for_input(timeout):
             return System._wait_for_input_posix(timeout)
         else:
             return System._wait_for_input_windows(timeout)
+
+    @staticmethod
+    def is_symlink(path):
+        if System.is_unix():
+            return os.path.islink(path)
+
+        # https://docs.microsoft.com/en-us/windows/desktop/fileio/
+        # file-attribute-constants
+        FILE_ATTRIBUTE_REPARSE_POINT = 0x400
+        info = System.getdirinfo(path)
+        return info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT
+
+    @staticmethod
+    def is_hardlink(path):
+        if System.is_unix():
+            return os.stat(path).st_nlink > 1
+
+        info = System.getdirinfo(path)
+        return info.nNumberOfLinks > 1