squashed commit

add change to do parallel zipping only, no crawling

modify cli arg format for medusa-zip tool

update cli arg format

fix non-exhaustive CopyMode usage

[BROKEN] add first run of complete medusa zip with cli arg!

the resulting zip cannot be zipimported yet....

medusa zipping works great now, let's revert .zip() changes

bump medusa options

bump more medusa options

use the merged medusa command lines now

manage a cache of parallel intermediate zip generation jobs!

small fix

much closer to mergeable now

working much more complex control flow between the medusa-zip cli

move medusa zip to medusa.py

medusa works for packed apps now too

works for everything, but kind of crazy

close stdin after writing to the child process

factor out a ridiculous amount of boilerplate

add back the non-medusa impl for packed layouts

implement a "normal" version which uses atomic directories

revert unintentional whitespace changes

separate the serial and parallel pex creations

remove the attempts at parallelism

add --medusa-path

remove unused code

make the medusa hook work when not provided

add back a tracer

revert some changes that make things harder to read

revert some changes i shouldn't need

make medusa work with the medusa-zip package and not subprocesses!

update after adding defaults in medusa-zip python package

remove -f arg for resolving medusa-zip

[BROKEN] possibly obsolete!

fix cli arg

add stitched layout

create stitch copymode

no

initial stitch impl

Author: cosmicexplorer

pex/common.py

@@ -25,6 +25,7 @@
 if TYPE_CHECKING:
     from typing import (
         Any,
+        BinaryIO,
         Callable,
         DefaultDict,
         Iterable,
@@ -34,6 +35,7 @@
         Set,
         Sized,
         Tuple,
+        Union,
     )
 
 # We use the start of MS-DOS time, which is what zipfiles use (see section 4.4.6 of
@@ -220,6 +222,7 @@ def _chmod(self, info, path):
 
 @contextlib.contextmanager
 def open_zip(path, *args, **kwargs):
+    # type: (Union[str, BinaryIO], Any, Any) -> Iterator[PermPreservingZipFile]
     """A contextmanager for zip files.
 
     Passes through positional and kwargs to zipfile.ZipFile.
@@ -585,7 +588,7 @@ def delete(self):
 
     def zip(
         self,
-        filename,  # type: str
+        output_file,  # type: Union[str, BinaryIO]
         mode="w",  # type: str
         deterministic_timestamp=False,  # type: bool
         exclude_file=lambda _: False,  # type: Callable[[str], bool]
@@ -603,7 +606,7 @@ def zip(
             selected_files = self.files()
 
         compression = zipfile.ZIP_DEFLATED if compress else zipfile.ZIP_STORED
-        with open_zip(filename, mode, compression) as zf:
+        with open_zip(output_file, mode, compression) as zf:
 
             def write_entry(
                 filename,  # type: str

pex/pex_builder.py

@@ -7,6 +7,8 @@
 import logging
 import os
 import shutil
+import subprocess
+from contextlib import contextmanager
 
 from pex import pex_warnings
 from pex.atomic_directory import atomic_directory
@@ -20,6 +22,7 @@
     safe_mkdir,
     safe_mkdtemp,
     safe_open,
+    temporary_dir,
 )
 from pex.compatibility import commonpath, to_bytes
 from pex.compiler import Compiler
@@ -28,6 +31,7 @@
 from pex.environment import PEXEnvironment
 from pex.finders import get_entry_point_from_console_script, get_script_from_distributions
 from pex.interpreter import PythonInterpreter
+from pex.jobs import Job
 from pex.layout import Layout
 from pex.orderedset import OrderedSet
 from pex.pex import PEX
@@ -37,9 +41,10 @@
 from pex.tracer import TRACER
 from pex.typing import TYPE_CHECKING
 from pex.util import CacheHelper
+from pex.ziputils import ZipCommand
 
 if TYPE_CHECKING:
-    from typing import Dict, Optional
+    from typing import BinaryIO, Callable, Dict, Iterator, Optional
 
 
 class CopyMode(Enum["CopyMode.Value"]):
@@ -88,14 +93,14 @@ def __maybe_run_venv__(pex, pex_root, pex_path):
 
   venv_dir = venv_dir(
     pex_file=pex,
-    pex_root=pex_root, 
+    pex_root=pex_root,
     pex_hash={pex_hash!r},
     has_interpreter_constraints={has_interpreter_constraints!r},
     pex_path=pex_path,
   )
   venv_pex = os.path.join(venv_dir, 'pex')
   if not __execute__ or not is_exe(venv_pex):
-    # Code in bootstrap_pex will (re)create the venv after selecting the correct interpreter. 
+    # Code in bootstrap_pex will (re)create the venv after selecting the correct interpreter.
     return venv_dir
 
   TRACER.log('Executing venv PEX for {{}} at {{}}'.format(pex, venv_pex))
@@ -434,6 +439,7 @@ def set_header(self, header):
         self._header = header
 
     def _add_dist_dir(self, path, dist_name, fingerprint=None):
+        # type: (str, str, Optional[str]) -> str
         target_dir = os.path.join(self._pex_info.internal_cache, dist_name)
         if self._copy_mode == CopyMode.SYMLINK:
             self._copy_or_link(path, target_dir, label=dist_name)
@@ -550,6 +556,7 @@ def _copy_or_link(self, src, dst, label=None):
         elif self._copy_mode == CopyMode.SYMLINK:
             self._chroot.symlink(src, dst, label)
         else:
+            assert self._copy_mode == CopyMode.LINK
             self._chroot.link(src, dst, label)
 
     def _prepare_bootstrap(self):
@@ -769,31 +776,144 @@ def zip_cache_dir(path):
                     os.path.join(internal_cache, location),
                 )
 
-    def _build_zipapp(
-        self,
-        filename,  # type: str
-        deterministic_timestamp=False,  # type: bool
-        compress=True,  # type: bool
-    ):
-        # type: (...) -> None
+    def _cache_dists_for_stitching(self, compress):
+        # type: (bool) -> Dict[str, str]
+        merge_deps = {}  # type: Dict[str, str]
+        with TRACER.timed("caching dists for stitched output", V=3):
+            for dist_label, fingerprint in self._pex_info.distributions.items():
+                cache_key = "{}-{}".format(
+                    fingerprint, "compressed" if compress else "uncompressed"
+                )
+                cached_zip = os.path.join(
+                    self._pex_info.pex_root,
+                    "stitched_dists",
+                    cache_key,
+                    dist_label,
+                )
+                with atomic_directory(os.path.dirname(cached_zip)) as atomic_zip_dir:
+                    if not atomic_zip_dir.is_finalized():
+                        atomic_output_file = os.path.join(
+                            atomic_zip_dir.work_dir, os.path.basename(cached_zip)
+                        )
+                        with TRACER.timed("caching single dist {}".format(dist_label), V=3):
+                            self._chroot.zip(
+                                atomic_output_file,
+                                labels=(dist_label,),
+                                deterministic_timestamp=True,
+                                compress=compress,
+                                exclude_file=is_pyc_temporary_file,
+                            )
+                assert os.path.isfile(cached_zip)
+                merge_deps[dist_label] = cached_zip
+
+            return merge_deps
+
+    @contextmanager
+    def _concatenate_cached_entries(self, zip_cmd, deterministic_timestamp, compress):
+        # type: (ZipCommand, bool, bool) -> Iterator[BinaryIO]
+        merge_deps = self._cache_dists_for_stitching(compress=compress)
+        uncached_labels = sorted(frozenset(self._chroot.labels()) - frozenset(merge_deps.keys()))
+
+        with TRACER.timed("synthesize zipapp", V=6), temporary_dir() as td:
+            concatenated_nonzip = os.path.join(td, "concatenated.broken-zip")
+            with open(concatenated_nonzip, "w+b") as concat_f:
+                with TRACER.timed("zipping up uncached sources", V=3):
+                    self._chroot.zip(
+                        concat_f,
+                        deterministic_timestamp=deterministic_timestamp,
+                        compress=compress,
+                        labels=uncached_labels,
+                    )
+
+                with TRACER.timed("concatenating cached dist zips", V=3):
+                    # Sort the cached zips by the prefixes of the filenames they'll be
+                    # inserting into the merged result, to get a deterministic output.
+                    for _, path in sorted(merge_deps.items(), key=lambda x: x[0]):
+                        with open(path, "rb") as f:
+                            shutil.copyfileobj(f, concat_f)  # type: ignore[misc]
+
+            fixed_zip = os.path.join(td, "fixed.zip")
+            zip_cmd.fix_concatenated_zips(concatenated_nonzip, fixed_zip)
+
+            with open(fixed_zip, "rb") as read_handle:
+                yield read_handle
+
+    @contextmanager
+    def _prepare_executable_zipapp(self, filename):
+        # type: (str) -> Iterator[BinaryIO]
         with safe_open(filename, "wb") as pexfile:
             assert os.path.getsize(pexfile.name) == 0
             pexfile.write(to_bytes("{}\n".format(self._shebang)))
             if self._header:
                 pexfile.write(to_bytes(self._header))
-        with TRACER.timed("Zipping PEX file."):
+
+            yield pexfile
+
+        chmod_plus_x(pexfile.name)
+
+    def _uncached_zipapp(
+        self,
+        filename,  # type: str
+        deterministic_timestamp,  # type: bool
+        compress,  # type: bool
+    ):
+        # type: (...) -> None
+
+        # When configured with a `copy_mode` of `CopyMode.SYMLINK`, we symlink distributions as
+        # pointers to installed wheel directories in ~/.pex/installed_wheels/... Since those
+        # installed wheels reside in a shared cache, they can be in-use by other processes and so
+        # their code may be in the process of being bytecode compiled as we attempt to zip up our
+        # chroot. Bytecode compilation produces ephemeral temporary pyc files that we should avoid
+        # copying since they are useless and inherently racy.
+        exclude_file = is_pyc_temporary_file
+
+        with TRACER.timed("Zipping PEX file."), self._prepare_executable_zipapp(
+            filename
+        ) as pexfile:
             self._chroot.zip(
-                filename,
-                mode="a",
+                pexfile,
                 deterministic_timestamp=deterministic_timestamp,
-                # When configured with a `copy_mode` of `CopyMode.SYMLINK`, we symlink distributions
-                # as pointers to installed wheel directories in ~/.pex/installed_wheels/... Since
-                # those installed wheels reside in a shared cache, they can be in-use by other
-                # processes and so their code may be in the process of being bytecode compiled as we
-                # attempt to zip up our chroot. Bytecode compilation produces ephemeral temporary
-                # pyc files that we should avoid copying since they are useless and inherently
-                # racy.
-                exclude_file=is_pyc_temporary_file,
                 compress=compress,
+                exclude_file=exclude_file,
             )
-        chmod_plus_x(filename)
+
+    def _build_zipapp(
+        self,
+        filename,  # type: str
+        deterministic_timestamp=False,  # type: bool
+        compress=True,  # type: bool
+    ):
+        # type: (...) -> None
+        # Naively creating a compressed zipapp with many downloaded distributions would perform
+        # a lot of I/O on each pex invocation and spend a lot of CPU on compression. While
+        # `--no-compress` runs significantly faster, the result may also be over twice as large.
+        should_try_synthesizing_from_cache = bool(self._pex_info.distributions) and compress
+        if not should_try_synthesizing_from_cache:
+            self._uncached_zipapp(
+                filename, deterministic_timestamp=deterministic_timestamp, compress=compress
+            )
+            return
+
+        # However, if we have access to the `zip` command, we can employ a caching strategy.
+        zip_cmd = ZipCommand.find()
+        if zip_cmd is None:
+            TRACER.log(
+                "`zip` command was not found, so compressed dist caches could not be used",
+                V=1,
+            )
+            self._uncached_zipapp(
+                filename, deterministic_timestamp=deterministic_timestamp, compress=compress
+            )
+            return
+
+        with TRACER.timed(
+            "cache dists and synthesize zipapp", V=9
+        ), self._concatenate_cached_entries(
+            zip_cmd,
+            deterministic_timestamp=deterministic_timestamp,
+            compress=compress,
+        ) as concatenated_zip_f:
+            with TRACER.timed(
+                "copying synthesized concatenated zip to output file", V=9
+            ), self._prepare_executable_zipapp(filename) as pexfile:
+                shutil.copyfileobj(concatenated_zip_f, pexfile)  # type: ignore[misc]

pex/ziputils.py

@@ -7,11 +7,14 @@
 import os
 import shutil
 import struct
+import subprocess
 
+from pex.jobs import Job
+from pex.tracer import TRACER
 from pex.typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from typing import BinaryIO, Optional
+    from typing import Any, BinaryIO, ClassVar, Optional
 
     import attr  # vendor:skip
 else:
@@ -242,3 +245,36 @@ def isolate_zip(self, out_fp):
             if self.has_header:
                 in_fp.seek(self.header_size, os.SEEK_SET)
             shutil.copyfileobj(in_fp, out_fp)
+
+
+@attr.s(frozen=True)
+class ZipCommand(object):
+    exe_path = attr.ib()  # type: str
+
+    _cached = None  # type: ClassVar[Optional[ZipCommand]]
+
+    @classmethod
+    def find(cls):
+        # type: () -> Optional[ZipCommand]
+        if cls._cached is not None:
+            return cls._cached
+
+        import distutils.spawn
+
+        zip_path = distutils.spawn.find_executable("zip")
+        if zip_path:
+            cls._cached = cls(exe_path=zip_path)
+        return cls._cached
+
+    def __call__(self, *args, **kwargs):
+        # type: (str, Any) -> Job
+        command = [self.exe_path] + list(args)
+        zip_proc = subprocess.Popen(
+            command, stdout=subprocess.DEVNULL, stderr=subprocess.PIPE, encoding="utf-8", **kwargs
+        )
+        return Job(command, zip_proc)
+
+    def fix_concatenated_zips(self, concatenated_zips_path, output_path):
+        # type: (str, str) -> None
+        with TRACER.timed("fixing up concatenated zips with `zip -FF`"):
+            self("-FF", concatenated_zips_path, "--out", output_path).wait()