packages: parse_pkgbuild(): banish SRCINFO caching into new file srcinfo_cache.py

packages/srcinfo_cache.py

@@ -0,0 +1,150 @@
+from __future__ import annotations
+
+import json
+import logging
+import os
+import subprocess
+
+from typing import Optional
+
+from config import config
+from constants import MAKEPKG_CMD, SRCINFO_FILE, SRCINFO_METADATA_FILE
+from dataclass import DataClass
+from exec.cmd import run_cmd
+from utils import sha256sum
+
+SRCINFO_CHECKSUM_FILES = ['PKGBUILD', SRCINFO_FILE]
+
+
+class SrcinfoMetaFile(DataClass):
+
+    class Checksums(DataClass):
+        PKGBUILD: str
+        SRCINFO: str
+
+    checksums: Checksums
+    build_mode: Optional[str]
+
+    _relative_path: str
+
+    @staticmethod
+    def parse_existing(relative_pkg_dir: str) -> SrcinfoMetaFile:
+        'tries to parse the srcinfo_meta.json file in the specified pkgbuild dir'
+        pkgdir = os.path.join(config.get_path('pkgbuilds'), relative_pkg_dir)
+        srcinfo_meta_file = os.path.join(pkgdir, SRCINFO_METADATA_FILE)
+        if not os.path.exists(srcinfo_meta_file):
+            raise Exception(f"{relative_pkg_dir}: {SRCINFO_METADATA_FILE} doesn't exist")
+        with open(srcinfo_meta_file, 'r') as meta_fd:
+            metadata_raw = json.load(meta_fd) | {'_relative_path': relative_pkg_dir}
+        return SrcinfoMetaFile.fromDict(metadata_raw, validate=True)
+
+    @staticmethod
+    def generate_new(relative_pkg_dir: str, write: bool = True) -> tuple[SrcinfoMetaFile, list[str]]:
+        'Creates a new SrcinfoMetaFile object with checksums, creating a SRCINFO as necessary'
+        s = SrcinfoMetaFile({'_relative_path': relative_pkg_dir, 'build_mode': '', 'checksums': {}}, validate=True)
+        return s, s.refresh_all()
+
+    @staticmethod
+    def handle_directory(relative_pkg_dir: str, force_refresh: bool = False, write: bool = True) -> tuple[SrcinfoMetaFile, list[str]]:
+        lines = None
+        # try reading existing cache metadata
+        try:
+            metadata = SrcinfoMetaFile.parse_existing(relative_pkg_dir)
+        except Exception as ex:
+            logging.debug(f"{relative_pkg_dir}: something went wrong parsing json from {SRCINFO_METADATA_FILE},"
+                          f"running `makepkg --printsrcinfo` instead instead: {ex}")
+            return SrcinfoMetaFile.generate_new(relative_pkg_dir, write=write)
+        # if for whatever reason only the SRCINFO got deleted but PKGBUILD has not been modified,
+        # we do want the checksum verification to work. So regenerate SRCINFO first.
+        if not os.path.exists(os.path.join(config.get_path('pkgbuilds'), relative_pkg_dir, SRCINFO_FILE)):
+            lines = metadata.refresh_srcinfo()
+        if not metadata.validate_checksums():
+            # metadata is invalid
+            return SrcinfoMetaFile.generate_new(relative_pkg_dir, write=write)
+        # metadata is valid
+        assert metadata
+        if not force_refresh:
+            logging.debug(f'{metadata._relative_path}: srcinfo checksums match!')
+            lines = lines or metadata.read_srcinfo_file()
+        else:
+            lines = metadata.refresh_all(write=write)
+        return metadata, lines
+
+    def refresh_checksums(self):
+        pkgdir = os.path.join(config.get_path('pkgbuilds'), self._relative_path)
+        checksums = self.Checksums({p: sha256sum(os.path.join(pkgdir, p)) for p in SRCINFO_CHECKSUM_FILES})
+        if 'checksums' not in self or self.checksums is None:
+            self['checksums'] = checksums
+        else:
+            self.checksums.clear()
+            self.checksums.update(checksums)
+
+    def refresh_build_mode(self):
+        self['build_mode'] = None
+        with open(os.path.join(config.get_path('pkgbuilds'), self._relative_path, 'PKGBUILD'), 'r') as file:
+            lines = file.read().split('\n')
+        for line in lines:
+            if line.startswith('_mode='):
+                self.build_mode = line.split('=', 1)[1].strip("\"'")
+                return
+
+    def refresh_srcinfo(self) -> list[str]:
+        'Run `makepkg --printsrcinfo` to create an updated SRCINFO file and return the lines from it'
+        logging.info(f"{self._relative_path}: Generating SRCINFO with makepkg")
+        pkgdir = os.path.join(config.get_path('pkgbuilds'), self._relative_path)
+        srcinfo_file = os.path.join(pkgdir, SRCINFO_FILE)
+        sproc = run_cmd(
+            MAKEPKG_CMD + ['--printsrcinfo'],
+            cwd=pkgdir,
+            stdout=subprocess.PIPE,
+        )
+        assert (isinstance(sproc, subprocess.CompletedProcess))
+        if sproc.returncode:
+            raise Exception(f"{self._relative_path}: makepkg failed to parse the PKGBUILD! Error code: {sproc.returncode}")
+        output = sproc.stdout.decode('utf-8')
+        with open(srcinfo_file, 'w') as srcinfo_fd:
+            srcinfo_fd.write(output)
+        return output.split('\n')
+
+    def read_srcinfo_file(self) -> list[str]:
+        with open(os.path.join(config.get_path('pkgbuilds'), self._relative_path, SRCINFO_FILE), 'r') as srcinfo_fd:
+            lines = srcinfo_fd.read().split('\n')
+        return lines
+
+    def refresh_all(self, write: bool = True) -> list[str]:
+        lines = self.refresh_srcinfo()
+        self.refresh_checksums()
+        self.refresh_build_mode()
+        if write:
+            self.write()
+        return lines
+
+    def validate_checksums(self) -> bool:
+        "Returns True if all checksummed files exist and checksums match"
+        pkgdir = os.path.join(config.get_path('pkgbuilds'), self._relative_path)
+        assert self.checksums
+        for filename in SRCINFO_CHECKSUM_FILES:
+            if filename not in self.checksums:
+                logging.debug(f"{self._relative_path}: No checksum for {filename} available")
+                return False
+            checksum = self.checksums[filename]
+            path = os.path.join(pkgdir, filename)
+            if not os.path.exists(path):
+                logging.debug(f"{self._relative_path}: can't checksum'{filename}: file doesn't exist")
+                return False
+            file_sum = sha256sum(path)
+            if file_sum != checksum:
+                logging.debug(f'{self._relative_path}: Checksum for file "{filename}" doesn\'t match')
+                return False
+        return True
+
+    def toJSON(self) -> str:
+        'Returns a json representation, with private keys that start with "_" filtered out'
+        return json.dumps({key: val for key, val in self.toDict().items() if not key.startswith('_')})
+
+    def write(self):
+        'Write the filtered json representation to disk as srcinfo_meta.json'
+        filepath = os.path.join(config.get_path('pkgbuilds'), self._relative_path, SRCINFO_METADATA_FILE)
+        logging.debug(f'{self._relative_path}: writing {SRCINFO_METADATA_FILE}')
+        with open(filepath, 'w') as fd:
+            fd.write(self.toJSON())