reuse pre-computed checksums

We calculate MD5 and SHA256 checksums as part of the log output
which might take considerable time.
Instead of recomputing it in `verify_checksum` we can reuse this value.

Author: Flamefire

easybuild/framework/easyblock.py

@@ -674,14 +674,16 @@ def collect_exts_file_info(self, fetch_files=True, verify_checksums=True):
                         src_fn = os.path.basename(src_path)
 
                         # report both MD5 and SHA256 checksums, since both are valid default checksum types
+                        src_checksums = {}
                         for checksum_type in (CHECKSUM_TYPE_MD5, CHECKSUM_TYPE_SHA256):
                             src_checksum = compute_checksum(src_path, checksum_type=checksum_type)
+                            src_checksums[checksum_type] = src_checksum
                             self.log.info("%s checksum for %s: %s", checksum_type, src_path, src_checksum)
 
                         # verify checksum (if provided)
                         self.log.debug('Verifying checksums for extension source...')
                         fn_checksum = self.get_checksum_for(checksums, filename=src_fn, index=0)
-                        if verify_checksum(src_path, fn_checksum):
+                        if verify_checksum(src_path, fn_checksum, src_checksums):
                             self.log.info('Checksum for extension source %s verified', src_fn)
                         elif build_option('ignore_checksums'):
                             print_warning("Ignoring failing checksum verification for %s" % src_fn)
@@ -700,12 +702,15 @@ def collect_exts_file_info(self, fetch_files=True, verify_checksums=True):
                         ext_src.update({'patches': ext_patches})
 
                         if verify_checksums:
+                            computed_checksums = {}
                             for patch in ext_patches:
                                 patch = patch['path']
+                                computed_checksums[patch] = {}
                                 # report both MD5 and SHA256 checksums,
                                 # since both are valid default checksum types
                                 for checksum_type in (CHECKSUM_TYPE_MD5, CHECKSUM_TYPE_SHA256):
                                     checksum = compute_checksum(patch, checksum_type=checksum_type)
+                                    computed_checksums[patch][checksum_type] = checksum
                                     self.log.info("%s checksum for %s: %s", checksum_type, patch, checksum)
 
                             # verify checksum (if provided)
@@ -715,7 +720,7 @@ def collect_exts_file_info(self, fetch_files=True, verify_checksums=True):
                                 patch_fn = os.path.basename(patch)
 
                                 checksum = self.get_checksum_for(checksums, filename=patch_fn, index=idx+1)
-                                if verify_checksum(patch, checksum):
+                                if verify_checksum(patch, checksum, computed_checksums[patch]):
                                     self.log.info('Checksum for extension patch %s verified', patch_fn)
                                 elif build_option('ignore_checksums'):
                                     print_warning("Ignoring failing checksum verification for %s" % patch_fn)

easybuild/tools/filetools.py

@@ -1242,7 +1242,7 @@ def calc_block_checksum(path, algorithm):
     return algorithm.hexdigest()
 
 
-def verify_checksum(path, checksums):
+def verify_checksum(path, checksums, computed_checksums=None):
     """
     Verify checksum of specified file.
 
@@ -1303,8 +1303,14 @@ def verify_checksum(path, checksums):
                                  "2-tuple (type, value), or tuple of alternative checksum specs.",
                                  checksum)
 
-        actual_checksum = compute_checksum(path, typ)
-        _log.debug("Computed %s checksum for %s: %s (correct checksum: %s)" % (typ, path, actual_checksum, checksum))
+        if computed_checksums is not None and typ in computed_checksums:
+            actual_checksum = computed_checksums[typ]
+            computed_str = 'Precomputed'
+        else:
+            actual_checksum = compute_checksum(path, typ)
+            computed_str = 'Computed'
+        _log.debug("%s %s checksum for %s: %s (correct checksum: %s)" %
+                   (computed_str, typ, path, actual_checksum, checksum))
 
         if actual_checksum != checksum:
             return False

test/framework/filetools.py

@@ -33,6 +33,7 @@
 """
 import datetime
 import glob
+import logging
 import os
 import re
 import shutil
@@ -297,10 +298,26 @@ def test_checksums(self):
                       'b7297da8b547d5e74b851d7c4e475900cec4744df0f887ae5c05bf1757c224b4',
         }
 
+        old_log_level = ft._log.getEffectiveLevel()
+        ft._log.setLevel(logging.DEBUG)
         # make sure checksums computation/verification is correct
         for checksum_type, checksum in known_checksums.items():
             self.assertEqual(ft.compute_checksum(fp, checksum_type=checksum_type), checksum)
-            self.assertTrue(ft.verify_checksum(fp, (checksum_type, checksum)))
+            with self.log_to_testlogfile():
+                self.assertTrue(ft.verify_checksum(fp, (checksum_type, checksum)))
+            self.assertIn('Computed ' + checksum_type, ft.read_file(self.logfile))
+            # Passing precomputed checksums reuses it
+            with self.log_to_testlogfile():
+                computed_checksums = {checksum_type: checksum}
+                self.assertTrue(ft.verify_checksum(fp, (checksum_type, checksum), computed_checksums))
+            self.assertIn('Precomputed ' + checksum_type, ft.read_file(self.logfile))
+            # If the type isn't contained the checksum will be computed
+            with self.log_to_testlogfile():
+                computed_checksums = {'doesnt exist': 'checksum'}
+                self.assertTrue(ft.verify_checksum(fp, (checksum_type, checksum), computed_checksums))
+            self.assertIn('Computed ' + checksum_type, ft.read_file(self.logfile))
+
+        ft._log.setLevel(old_log_level)
 
         # default checksum type is MD5
         self.assertEqual(ft.compute_checksum(fp), known_checksums['md5'])