Merge pull request #11 from desultory/dev

Add compression tests, level setting

Author: desultory

completion/_pycpio

@@ -24,8 +24,8 @@ args=("-i[input archive]:archive:_files"
       "--set-group[GID]:GID:_groups"
       "-m[file mode]:mode"
       "--set-mode[file modes]:mode"
-      "-z[compression]:compression:(xz)"
-      "--compress[compression]:compression:(xz)"
+      "-z[compression]:compression:(xz zstd)"
+      "--compress[compression]:compression:(xz zstd)"
       "-o[output archive]:archive:_files"
       "--output[output archive]:archive:_files"
       "--log-file[specify the log file]:log file:_files"

readme.md

@@ -6,7 +6,9 @@
 
 A library for creating CPIO files in Python.
 
-Currently, the library only supports the New ASCII format, and xz compression
+Currently, the library only supports the New ASCII format.
+
+xz compression and zstd compression types are suppored.
 
 This library is primary designed for use in [ugrd](https://github.com/desultory/ugrd) to create CPIO archives for use in initramfs.
 

src/pycpio/writer/writer.py

@@ -20,6 +20,7 @@ def __init__(
         output_file: Path,
         structure=None,
         compression=False,
+        compression_level=10,
         xz_crc=CHECK_CRC32,
         *args,
         **kwargs,
@@ -30,6 +31,7 @@ def __init__(
         self.structure = structure if structure is not None else HEADER_NEW
 
         self.compression = compression or False
+        self.compression_level = compression_level or 10
         if isinstance(compression, str):
             compression = compression.lower()
             if compression == "true":
@@ -50,18 +52,36 @@ def __bytes__(self):
 
     def compress(self, data):
         """Attempts to compress the data using the specified compression type."""
+        compression_kwargs = {}
+        compression_args = ()
         if self.compression == "xz" or self.compression is True:
-            import lzma
-
-            self.logger.info("XZ compressing the CPIO data, original size: %.2f MiB" % (len(data) / (2**20)))
-            data = lzma.compress(data, check=self.xz_crc)
+            compression_module = "lzma.compress"
+            compression_kwargs["check"] = self.xz_crc
         elif self.compression == "zstd":
-            import zstd
-
-            self.logger.info("ZSTD compressing the CPIO data, original size: %.2f MiB" % (len(data) / (2**20)))
-            data = zstd.compress(data, 10)
+            compression_module = "zstd.compress"
+            compression_args = (self.compression_level,)
         elif self.compression is not False:
             raise NotImplementedError("Compression type not supported: %s" % self.compression)
+        else:
+            self.logger.info("No compression specified, writing uncompressed data.")
+            return data
+
+        try:
+            if "." in compression_module:
+                module, func = compression_module.rsplit(".", 1)
+            else:
+                module, func = compression_module, "compress"
+
+            compressor = getattr(__import__(module), func)
+            self.logger.debug("Compressing data with: %s" % compression_module)
+        except ImportError as e:
+            raise ImportError("Failed to import compression module: %s" % compression_module) from e
+
+        self.logger.info(
+            "[%s] Compressing the CPIO data, original size: %.2f MiB" % (self.compression.upper(), len(data) / (2**20))
+        )
+        data = compressor(data, *compression_args, **compression_kwargs)
+
         return data
 
     def write(self, safe_write=True):

tests/test_compression.py

@@ -0,0 +1,79 @@
+from tempfile import NamedTemporaryFile, TemporaryDirectory
+from unittest import TestCase, main
+from uuid import uuid4
+
+from pycpio import PyCPIO
+from zenlib.logging import loggify
+
+
+@loggify
+class TestCpio(TestCase):
+    def setUp(self):
+        self.cpio = PyCPIO(logger=self.logger)
+        self.make_workdir()
+
+    def tearDown(self):
+        for file in self.test_files:
+            file.close()
+        for directory in self.test_dirs:
+            directory.cleanup()
+        self.workdir.cleanup()
+        del self.cpio
+
+    def make_workdir(self):
+        """
+        Create a temporary directory for testing.
+        sets self.workdir to the Path object of the directory
+        initializes self.test_files as an empty list
+        """
+        self.workdir = TemporaryDirectory(prefix="pycpio-test-")
+        self.test_files = []
+        self.test_dirs = []
+
+    def make_test_file(self, subdir=None, data=None):
+        """Creates a test file in the workdir"""
+        base_dir = self.workdir.name
+        if subdir is True:
+            d = TemporaryDirectory(dir=base_dir)
+            self.test_dirs.append(d)
+            base_dir = d.name
+        elif subdir is not None and subdir in self.test_dirs:
+            base_dir = subdir.name
+
+        file = NamedTemporaryFile(dir=base_dir)
+        file_data = data.encode() if data is not None else bytes(str(uuid4()), "utf-8")
+        file.file.write(file_data)
+        file.file.flush()
+
+        self.test_files.append(file)
+        return file
+
+    def make_test_files(self, count, subdir=None, data=None):
+        """Creates count test files in the workdir"""
+        for _ in range(count):
+            self.make_test_file(subdir=subdir, data=data)
+
+    def test_write_no_compress(self):
+        self.make_test_files(100)
+        self.cpio.append_cpio(self.workdir.name)
+        out_file = NamedTemporaryFile()  # Out file for the cpio
+        self.cpio.write_cpio_file(out_file.file.name)
+        out_file.file.flush()
+
+    def test_write_xz_compress(self):
+        self.make_test_files(100)
+        self.cpio.append_cpio(self.workdir.name)
+        out_file = NamedTemporaryFile()
+        self.cpio.write_cpio_file(out_file.file.name, compress="xz")
+        out_file.file.flush()
+
+    def test_write_zstd_compress(self):
+        self.make_test_files(100)
+        self.cpio.append_cpio(self.workdir.name)
+        out_file = NamedTemporaryFile()
+        self.cpio.write_cpio_file(out_file.file.name, compress="zstd")
+        out_file.file.flush()
+
+
+if __name__ == "__main__":
+    main()