changeset 41913:c2237fe1359e

packaging: split downloading code into own module

As we will introduce more code to support packaging, it will be
useful to have download code in its own module.

Differential Revision: https://phab.mercurial-scm.org/D6084

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/packaging/hgpackaging/downloads.py	Thu Mar 07 15:42:32 2019 -0800
@@ -0,0 +1,116 @@
+# downloads.py - Code for downloading dependencies.
+#
+# Copyright 2019 Gregory Szorc <[e-mail]>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+# no-check-code because Python 3 native.
+
+import gzip
+import hashlib
+import pathlib
+import urllib.request
+
+
+def hash_path(p: pathlib.Path):
+    h = hashlib.sha256()
+
+    with p.open('rb') as fh:
+        while True:
+            chunk = fh.read(65536)
+            if not chunk:
+                break
+
+            h.update(chunk)
+
+    return h.hexdigest()
+
+
+class IntegrityError(Exception):
+    """Represents an integrity error when downloading a URL."""
+
+
+def secure_download_stream(url, size, sha256):
+    """Securely download a URL to a stream of chunks.
+
+    If the integrity of the download fails, an IntegrityError is
+    raised.
+    """
+    h = hashlib.sha256()
+    length = 0
+
+    with urllib.request.urlopen(url) as fh:
+        if not url.endswith('.gz') and fh.info().get('Content-Encoding') == 'gzip':
+            fh = gzip.GzipFile(fileobj=fh)
+
+        while True:
+            chunk = fh.read(65536)
+            if not chunk:
+                break
+
+            h.update(chunk)
+            length += len(chunk)
+
+            yield chunk
+
+    digest = h.hexdigest()
+
+    if length != size:
+        raise IntegrityError('size mismatch on %s: wanted %d; got %d' % (
+            url, size, length))
+
+    if digest != sha256:
+        raise IntegrityError('sha256 mismatch on %s: wanted %s; got %s' % (
+            url, sha256, digest))
+
+
+def download_to_path(url: str, path: pathlib.Path, size: int, sha256: str):
+    """Download a URL to a filesystem path, possibly with verification."""
+
+    # We download to a temporary file and rename at the end so there's
+    # no chance of the final file being partially written or containing
+    # bad data.
+    print('downloading %s to %s' % (url, path))
+
+    if path.exists():
+        good = True
+
+        if path.stat().st_size != size:
+            print('existing file size is wrong; removing')
+            good = False
+
+        if good:
+            if hash_path(path) != sha256:
+                print('existing file hash is wrong; removing')
+                good = False
+
+        if good:
+            print('%s exists and passes integrity checks' % path)
+            return
+
+        path.unlink()
+
+    tmp = path.with_name('%s.tmp' % path.name)
+
+    try:
+        with tmp.open('wb') as fh:
+            for chunk in secure_download_stream(url, size, sha256):
+                fh.write(chunk)
+    except IntegrityError:
+        tmp.unlink()
+        raise
+
+    tmp.rename(path)
+    print('successfully downloaded %s' % url)
+
+
+def download_entry(entry: dict, dest_path: pathlib.Path, local_name=None) -> pathlib.Path:
+    url = entry['url']
+
+    local_name = local_name or url[url.rindex('/') + 1:]
+
+    local_path = dest_path / local_name
+    download_to_path(url, local_path, entry['size'], entry['sha256'])
+
+    return local_path

--- a/contrib/packaging/hgpackaging/util.py	Thu Mar 07 10:10:04 2019 -0800
+++ b/contrib/packaging/hgpackaging/util.py	Thu Mar 07 15:42:32 2019 -0800
@@ -7,117 +7,11 @@
 
 # no-check-code because Python 3 native.
 
-import gzip
-import hashlib
 import pathlib
 import tarfile
-import urllib.request
 import zipfile
 
 
-def hash_path(p: pathlib.Path):
-    h = hashlib.sha256()
-
-    with p.open('rb') as fh:
-        while True:
-            chunk = fh.read(65536)
-            if not chunk:
-                break
-
-            h.update(chunk)
-
-    return h.hexdigest()
-
-
-class IntegrityError(Exception):
-    """Represents an integrity error when downloading a URL."""
-
-
-def secure_download_stream(url, size, sha256):
-    """Securely download a URL to a stream of chunks.
-
-    If the integrity of the download fails, an IntegrityError is
-    raised.
-    """
-    h = hashlib.sha256()
-    length = 0
-
-    with urllib.request.urlopen(url) as fh:
-        if not url.endswith('.gz') and fh.info().get('Content-Encoding') == 'gzip':
-            fh = gzip.GzipFile(fileobj=fh)
-
-        while True:
-            chunk = fh.read(65536)
-            if not chunk:
-                break
-
-            h.update(chunk)
-            length += len(chunk)
-
-            yield chunk
-
-    digest = h.hexdigest()
-
-    if length != size:
-        raise IntegrityError('size mismatch on %s: wanted %d; got %d' % (
-            url, size, length))
-
-    if digest != sha256:
-        raise IntegrityError('sha256 mismatch on %s: wanted %s; got %s' % (
-            url, sha256, digest))
-
-
-def download_to_path(url: str, path: pathlib.Path, size: int, sha256: str):
-    """Download a URL to a filesystem path, possibly with verification."""
-
-    # We download to a temporary file and rename at the end so there's
-    # no chance of the final file being partially written or containing
-    # bad data.
-    print('downloading %s to %s' % (url, path))
-
-    if path.exists():
-        good = True
-
-        if path.stat().st_size != size:
-            print('existing file size is wrong; removing')
-            good = False
-
-        if good:
-            if hash_path(path) != sha256:
-                print('existing file hash is wrong; removing')
-                good = False
-
-        if good:
-            print('%s exists and passes integrity checks' % path)
-            return
-
-        path.unlink()
-
-    tmp = path.with_name('%s.tmp' % path.name)
-
-    try:
-        with tmp.open('wb') as fh:
-            for chunk in secure_download_stream(url, size, sha256):
-                fh.write(chunk)
-    except IntegrityError:
-        tmp.unlink()
-        raise
-
-    tmp.rename(path)
-    print('successfully downloaded %s' % url)
-
-
-def download_entry(entry: dict, dest_path: pathlib.Path, local_name=None) -> pathlib.Path:
-    url = entry['url']
-
-    local_name = local_name or url[url.rindex('/') + 1:]
-
-    local_path = dest_path / local_name
-    download_to_path(url, local_path, entry['size'], entry['sha256'])
-
-    return local_path
-
-
 def extract_tar_to_directory(source: pathlib.Path, dest: pathlib.Path):
     with tarfile.open(source, 'r') as tf:
         tf.extractall(dest)

--- a/contrib/packaging/inno/build.py	Thu Mar 07 10:10:04 2019 -0800
+++ b/contrib/packaging/inno/build.py	Thu Mar 07 15:42:32 2019 -0800
@@ -87,8 +87,10 @@
     for finding the Python 2.7 toolchain. So, we require the environment
     to already be configured with an active toolchain.
     """
+    from hgpackaging.downloads import (
+        download_entry,
+    )
     from hgpackaging.util import (
-        download_entry,
         extract_tar_to_directory,
         extract_zip_to_directory,
     )

--- a/tests/test-check-code.t	Thu Mar 07 10:10:04 2019 -0800
+++ b/tests/test-check-code.t	Thu Mar 07 15:42:32 2019 -0800
@@ -12,6 +12,7 @@
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/thirdparty \
   > | sed 's-\\-/-g' | "$check_code" --warnings --per-file=0 - || false
+  Skipping contrib/packaging/hgpackaging/downloads.py it has no-che?k-code (glob)
   Skipping contrib/packaging/hgpackaging/util.py it has no-che?k-code (glob)
   Skipping contrib/packaging/inno/build.py it has no-che?k-code (glob)
   Skipping i18n/polib.py it has no-che?k-code (glob)