perf: more extensive caching of source files, including wrappers.

docs/snakefiles/deployment.rst

@@ -69,14 +69,20 @@ Consider the following example:
     configfile: "config/config.yaml"
 
     module dna_seq:
-        snakefile: "https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/raw/v2.0.1/Snakefile"
-        config: config
+        snakefile:
+            # here, it is also possible to provide a plain raw URL like "https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/raw/v2.0.1/workflow/Snakefile"
+            github("snakemake-workflows/dna-seq-gatk-variant-calling", path="workflow/Snakefile" tag="v2.0.1")
+        config:
+            config
 
     use rule * from dna_seq
 
 First, we load a local configuration file.
-Next, we define the module ``dna_seq`` to be loaded from the URL ``https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/blob/v2.0.1/Snakefile``, while using the contents of the local configuration file.
+Next, we define the module ``dna_seq`` to be loaded from the URL ``https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/raw/v2.0.1/workflow/Snakefile``, while using the contents of the local configuration file.
+Note that it is possible to either specify the full URL pointing to the raw Snakefile as a string or to use the github marker as done here.
+With the latter, Snakemake can however cache the used source files persistently (if a tag is given), such that they don't have to be downloaded on each invocation.
 Finally we declare all rules of the dna_seq module to be used.
+
 This kind of deployment is equivalent to just cloning the original repository and modifying the configuration in it.
 However, the advantage here is that we are (a) able to easily extend of modify the workflow, while making the changes transparent, and (b) we can store this workflow in a separate (e.g. private) git repository, along with for example configuration and meta data, without the need to duplicate the workflow code.
 Finally, we are always able to later combine another module into the current workflow, e.g. when further kinds of analyses are needed.
@@ -92,7 +98,9 @@ For example, we can easily add another rule to extend the given workflow:
     configfile: "config/config.yaml"
 
     module dna_seq:
-        snakefile: "https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/raw/v2.0.1/Snakefile"
+        snakefile:
+            # here, it is also possible to provide a plain raw URL like "https://github.com/snakemake-workflows/dna-seq-gatk-variant-calling/raw/v2.0.1/workflow/Snakefile"
+            github("snakemake-workflows/dna-seq-gatk-variant-calling", path="workflow/Snakefile" tag="v2.0.1")
         config: config
 
     use rule * from dna_seq
@@ -106,6 +114,8 @@ For example, we can easily add another rule to extend the given workflow:
         notebook:
             "notebooks/plot-vafs.py.ipynb"
 
+Moreover, it is possible to further extend the workflow with other modules, thereby generating an integrative analysis.
+
 ----------------------------------
 Uploading workflows to WorkflowHub
 ----------------------------------

docs/snakefiles/modularization.rst

@@ -126,12 +126,14 @@ With Snakemake 6.0 and later, it is possible to define external workflows as mod
     min_version("6.0")
 
     module other_workflow:
-        snakefile: "other_workflow/Snakefile"
+        snakefile:
+            # here, plain paths, URLs and the special markers for code hosting providers (see below) are possible.
+            "other_workflow/Snakefile"
 
     use rule * from other_workflow as other_*
 
 The first statement registers the external workflow as a module, by defining the path to the main snakefile.
-The snakefile property of the module can either take a local path or a HTTP/HTTPS url.
+Here, plain paths, HTTP/HTTPS URLs and special markers for code hosting providers like Github or Gitlab are possible (see :ref:`snakefile-code-hosting-providers`).
 The second statement declares all rules of that module to be used in the current one.
 Thereby, the ``as other_*`` at the end renames all those rule with a common prefix.
 This can be handy to avoid rule name conflicts (note that rules from modules can otherwise overwrite rules from your current workflow or other modules).
@@ -149,6 +151,7 @@ It is possible to overwrite the global config dictionary for the module, which i
     configfile: "config/config.yaml"
 
     module other_workflow:
+        # here, plain paths, URLs and the special markers for code hosting providers (see below) are possible.
         snakefile: "other_workflow/Snakefile"
         config: config["other-workflow"]
 
@@ -167,6 +170,7 @@ This modification can be performed after a general import, and will overwrite an
     min_version("6.0")
 
     module other_workflow:
+        # here, plain paths, URLs and the special markers for code hosting providers (see below) are possible.
         snakefile: "other_workflow/Snakefile"
         config: config["other-workflow"]
 
@@ -261,3 +265,34 @@ This function automatically determines the absolute path to the file (here ``../
 When executing, snakemake first tries to create (or update, if necessary) ``test.txt`` (and all other possibly mentioned dependencies) by executing the subworkflow.
 Then the current workflow is executed.
 This can also happen recursively, since the subworkflow may have its own subworkflows as well.
+
+
+.. _snakefile-code-hosting-providers:
+
+----------------------
+Code hosting providers
+----------------------
+
+To obtain the correct URL to an external source code resource (e.g. a snakefile, see :ref:`snakefiles-modules`), Snakemake provides markers for code hosting providers.
+Currently, Github 
+
+.. code-block:: python
+
+    github("owner/repo", path="workflow/Snakefile", tag="v1.0.0")
+
+
+and Gitlab are supported:
+
+.. code-block:: python
+
+    gitlab("owner/repo", path="workflow/Snakefile", tag="v1.0.0")
+
+For the latter, it is also possible to specify an alternative host, e.g.
+
+.. code-block:: python
+
+    gitlab("owner/repo", path="workflow/Snakefile", tag="v1.0.0", host="somecustomgitlab.org")
+
+
+While specifying a tag is highly encouraged, it is alternatively possible to specify a `commit` or a `branch` via respective keyword arguments.
+Note that only when specifying a tag or a commit, Snakemake is able to persistently cache the source, thereby avoiding to repeatedly query it in case of multiple executions.

snakemake/cwl.py

@@ -35,6 +35,7 @@ def cwl(
     use_singularity,
     bench_record,
     jobid,
+    runtime_sourcecache_path,
 ):
     """
     Load cwl from the given basedir + path and execute it.

snakemake/deployment/conda.py

@@ -5,6 +5,7 @@
 
 import os
 import re
+from snakemake.sourcecache import LocalGitFile, LocalSourceFile, infer_source_file
 import subprocess
 import tempfile
 from urllib.request import urlopen
@@ -45,7 +46,7 @@ class Env:
     def __init__(
         self, env_file, workflow, env_dir=None, container_img=None, cleanup=None
     ):
-        self.file = env_file
+        self.file = infer_source_file(env_file)
 
         self.frontend = workflow.conda_frontend
         self.workflow = workflow
@@ -161,7 +162,9 @@ def create_archive(self):
         try:
             # Download
             logger.info(
-                "Downloading packages for conda environment {}...".format(self.file)
+                "Downloading packages for conda environment {}...".format(
+                    self.file.get_path_or_uri()
+                )
             )
             os.makedirs(env_archive, exist_ok=True)
             try:
@@ -216,11 +219,16 @@ def create(self, dryrun=False):
         env_file = self.file
         tmp_file = None
 
-        if not is_local_file(env_file) or env_file.startswith("git+file:/"):
+        if not isinstance(env_file, LocalSourceFile) or isinstance(
+            env_file, LocalGitFile
+        ):
             with tempfile.NamedTemporaryFile(delete=False, suffix=".yaml") as tmp:
+                # write to temp file such that conda can open it
                 tmp.write(self.content)
                 env_file = tmp.name
                 tmp_file = tmp.name
+        else:
+            env_file = env_file.get_path_or_uri()
 
         env_hash = self.hash
         env_path = self.path
@@ -258,13 +266,13 @@ def create(self, dryrun=False):
             if dryrun:
                 logger.info(
                     "Incomplete Conda environment {} will be recreated.".format(
-                        utils.simplify_path(self.file)
+                        self.file.simplify_path()
                     )
                 )
             else:
                 logger.info(
                     "Removing incomplete Conda environment {}...".format(
-                        utils.simplify_path(self.file)
+                        self.file.simplify_path()
                     )
                 )
                 shutil.rmtree(env_path, ignore_errors=True)
@@ -274,15 +282,13 @@ def create(self, dryrun=False):
             if dryrun:
                 logger.info(
                     "Conda environment {} will be created.".format(
-                        utils.simplify_path(self.file)
+                        self.file.simplify_path()
                     )
                 )
                 return env_path
             conda = Conda(self._container_img)
             logger.info(
-                "Creating conda environment {}...".format(
-                    utils.simplify_path(self.file)
-                )
+                "Creating conda environment {}...".format(self.file.simplify_path())
             )
             # Check if env archive exists. Use that if present.
             env_archive = self.archive_file

snakemake/exceptions.py

@@ -164,6 +164,11 @@ def __init__(self, *args, lineno=None, snakefile=None, rule=None):
         self.rule = rule
 
 
+class SourceFileError(WorkflowError):
+    def __init__(self, msg):
+        super().__init__("Error in source file definition: {}".format(msg))
+
+
 class WildcardError(WorkflowError):
     pass
 

snakemake/executors/__init__.py

@@ -515,6 +515,7 @@ def job_args_and_prepare(self, job):
             self.workflow.edit_notebook,
             self.workflow.conda_base_path,
             job.rule.basedir,
+            self.workflow.sourcecache.runtime_cache_path,
         )
 
     def run_single_job(self, job):
@@ -2296,6 +2297,7 @@ def run_wrapper(
     edit_notebook,
     conda_base_path,
     basedir,
+    runtime_sourcecache_path,
 ):
     """
     Wrapper around the run method that handles exceptions and benchmarking.
@@ -2376,6 +2378,7 @@ def run_wrapper(
                             edit_notebook,
                             conda_base_path,
                             basedir,
+                            runtime_sourcecache_path,
                         )
                     else:
                         # The benchmarking is started here as we have a run section
@@ -2406,6 +2409,7 @@ def run_wrapper(
                                 edit_notebook,
                                 conda_base_path,
                                 basedir,
+                                runtime_sourcecache_path,
                             )
                     # Store benchmark record for this iteration
                     bench_records.append(bench_record)
@@ -2434,20 +2438,26 @@ def run_wrapper(
                     edit_notebook,
                     conda_base_path,
                     basedir,
+                    runtime_sourcecache_path,
                 )
     except (KeyboardInterrupt, SystemExit) as e:
         # Re-raise the keyboard interrupt in order to record an error in the
         # scheduler but ignore it
         raise e
     except (Exception, BaseException) as ex:
-        log_verbose_traceback(ex)
         # this ensures that exception can be re-raised in the parent thread
-        lineno, file = get_exception_origin(ex, linemaps)
-        raise RuleException(
-            format_error(
-                ex, lineno, linemaps=linemaps, snakefile=file, show_traceback=True
+        origin = get_exception_origin(ex, linemaps)
+        if origin is not None:
+            log_verbose_traceback(ex)
+            lineno, file = origin
+            raise RuleException(
+                format_error(
+                    ex, lineno, linemaps=linemaps, snakefile=file, show_traceback=True
+                )
             )
-        )
+        else:
+            # some internal bug, just reraise
+            raise ex
 
     if benchmark is not None:
         try:

snakemake/io.py

@@ -1345,11 +1345,11 @@ def git_content(git_file):
     """
     This function will extract a file from a git repository, one located on
     the filesystem.
-    Expected format is git+file:///path/to/your/repo/path_to_file@@version
+    Expected format is git+file:///path/to/your/repo/path_to_file@version
 
     Args:
       env_file (str): consist of path to repo, @, version and file information
-                      Ex: git+file:////home/smeds/snakemake-wrappers/bio/fastqc/wrapper.py@0.19.3
+                      Ex: git+file:///home/smeds/snakemake-wrappers/bio/fastqc/wrapper.py@0.19.3
     Returns:
         file content or None if the expected format isn't meet
     """

snakemake/notebook.py

@@ -10,6 +10,7 @@
 from snakemake.logging import logger
 from snakemake.common import is_local_file
 from snakemake.common import ON_WINDOWS
+from snakemake.sourcecache import SourceCache
 
 KERNEL_STARTED_RE = re.compile(r"Kernel started: (?P<kernel_id>\S+)")
 KERNEL_SHUTDOWN_RE = re.compile(r"Kernel shutdown: (?P<kernel_id>\S+)")
@@ -152,6 +153,7 @@ def get_preamble(self):
             self.bench_iteration,
             self.cleanup_scripts,
             self.shadow_dir,
+            self.is_local,
             preamble_addendum=preamble_addendum,
         )
 
@@ -218,7 +220,8 @@ def notebook(
     bench_iteration,
     cleanup_scripts,
     shadow_dir,
-    edit=None,
+    edit,
+    runtime_sourcecache_path,
 ):
     """
     Load a script from the given basedir + path and execute it.
@@ -251,9 +254,12 @@ def notebook(
             )
 
     if not draft:
-        path, source, language = get_source(path, basedir, wildcards, params)
+        path, source, language, is_local = get_source(
+            path, SourceCache(runtime_sourcecache_path), basedir, wildcards, params
+        )
     else:
         source = None
+        is_local = True
 
     exec_class = get_exec_class(language)
 
@@ -280,6 +286,7 @@ def notebook(
         bench_iteration,
         cleanup_scripts,
         shadow_dir,
+        is_local,
     )
 
     if draft:

snakemake/parser.py

@@ -507,7 +507,7 @@ def start(self):
             "resources, log, version, rule, conda_env, container_img, "
             "singularity_args, use_singularity, env_modules, bench_record, jobid, "
             "is_shell, bench_iteration, cleanup_scripts, shadow_dir, edit_notebook, "
-            "conda_base_path, basedir):".format(
+            "conda_base_path, basedir, runtime_sourcecache_path):".format(
                 rulename=self.rulename
                 if self.rulename is not None
                 else self.snakefile.rulecount
@@ -608,7 +608,7 @@ def args(self):
         yield (
             ", basedir, input, output, params, wildcards, threads, resources, log, "
             "config, rule, conda_env, conda_base_path, container_img, singularity_args, env_modules, "
-            "bench_record, jobid, bench_iteration, cleanup_scripts, shadow_dir"
+            "bench_record, jobid, bench_iteration, cleanup_scripts, shadow_dir, runtime_sourcecache_path"
         )
 
 
@@ -621,7 +621,7 @@ def args(self):
             ", basedir, input, output, params, wildcards, threads, resources, log, "
             "config, rule, conda_env, conda_base_path, container_img, singularity_args, env_modules, "
             "bench_record, jobid, bench_iteration, cleanup_scripts, shadow_dir, "
-            "edit_notebook"
+            "edit_notebook, runtime_sourcecache_path"
         )
 
 
@@ -634,7 +634,7 @@ def args(self):
             ", input, output, params, wildcards, threads, resources, log, "
             "config, rule, conda_env, conda_base_path, container_img, singularity_args, env_modules, "
             "bench_record, workflow.wrapper_prefix, jobid, bench_iteration, "
-            "cleanup_scripts, shadow_dir"
+            "cleanup_scripts, shadow_dir, runtime_sourcecache_path"
         )
 
 
@@ -645,7 +645,7 @@ class CWL(Script):
     def args(self):
         yield (
             ", basedir, input, output, params, wildcards, threads, resources, log, "
-            "config, rule, use_singularity, bench_record, jobid"
+            "config, rule, use_singularity, bench_record, jobid, runtime_sourcecache_path"
         )
 
 
@@ -1157,7 +1157,7 @@ def python(self, token):
 
 class Snakefile:
     def __init__(self, path, workflow, rulecount=0):
-        self.path = path
+        self.path = path.get_path_or_uri()
         self.file = workflow.sourcecache.open(path)
         self.tokens = tokenize.generate_tokens(self.file.readline)
         self.rulecount = rulecount