| 0,0 → 1,196 |
|---|
| <?php |
| |
| /* |
| * PHP git functions |
| * Copyright 2021 Daniel Marschall, ViaThinkSoft |
| * Revision 2021-10-03 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| function git_get_latest_commit_message($git_dir) { |
| $cont = file_get_contents($git_dir.'/HEAD'); |
| if (!preg_match('@ref: (.+)[\r\n]@', "$cont\n", $m)) throw new Exception("Cannot find HEAD ref"); |
| $commit_object = trim(file_get_contents($git_dir.'/'.$m[1])); |
| |
| $objects_dir = $git_dir . '/objects'; |
| |
| $pack_files = glob($objects_dir.'\pack\pack-*.pack'); |
| foreach ($pack_files as $basename) { |
| $basename = substr(basename($basename),0,strlen(basename($basename))-5); |
| try { |
| return git_read_object($commit_object, |
| $objects_dir.'/pack/'.$basename.'.idx', |
| $objects_dir.'/pack/'.$basename.'.pack', |
| false |
| ); |
| } catch (Exception $e) { |
| $last_exception = $e; |
| } |
| } |
| throw new Exception($last_exception); |
| } |
| |
| function git_read_object($object_wanted, $idx_file, $pack_file, $debug=false) { |
| // More info about the IDX and PACK format: https://git-scm.com/docs/pack-format |
| |
| // Do some checks |
| if (!preg_match('/^[0-9a-fA-F]{40}$/', $object_wanted, $m)) throw new Exception("Is not a valid object: $object_wanted"); |
| if (!file_exists($idx_file)) throw new Exception("Idx file $idx_file not found"); |
| if (!file_exists($pack_file)) throw new Exception("Pack file $pack_file not found"); |
| |
| // Open index file |
| $fp = fopen($idx_file, 'rb'); |
| if (!$fp) throw new Exception("Cannot open index file $idx_file"); |
| |
| // Read version |
| fseek($fp, 0); |
| $unpacked = unpack('N', fread($fp, 4)); // vorzeichenloser Long-Typ (immer 32 Bit, Byte-Folge Big-Endian) |
| if ($unpacked[1] === 0xFF744F63) { |
| $version = unpack('N', fread($fp, 4))[1]; // vorzeichenloser Long-Typ (immer 32 Bit, Byte-Folge Big-Endian) |
| $fanout_offset = 8; |
| if ($version != 2) throw new Exception("Version $version unknown"); |
| } else { |
| $version = 1; |
| $fanout_offset = 0; |
| } |
| if ($debug) echo "Index file version = $version\n"; |
| |
| // Read fanout table |
| fseek($fp, $fanout_offset); |
| $fanout_ary[0] = 0; |
| $fanout_ary = unpack('N*', fread($fp, 4*256)); |
| $num_objects = $fanout_ary[256]; |
| |
| // Find out approximate object number (from fanout table) |
| $fanout_index = hexdec(substr($object_wanted,0,2)); |
| if ($debug) echo "Fanout index = ".($fanout_index-1)."\n"; |
| $object_no = $fanout_ary[$fanout_index]; // approximate |
| if ($debug) echo "Object no approx $object_no\n"; |
| |
| // Find the exact object number |
| fseek($fp, $fanout_offset + 4*256 + 20*$object_no); |
| $object_no--; |
| do { |
| $object_no++; |
| if ($version == 1) { |
| $pack_offset = fread($fp, 4); |
| } |
| $binary = fread($fp, 20); |
| if (substr(bin2hex($binary),0,2) != substr(strtolower($object_wanted),0,2)) { |
| throw new Exception("Object $object_wanted not found"); |
| } |
| } while (bin2hex($binary) != strtolower($object_wanted)); |
| if ($debug) echo "Exact object no = $object_no\n"; |
| |
| if ($version == 2) { |
| // Get CRC32 |
| fseek($fp, $fanout_offset + 4*256 + 20*$num_objects + 4*$object_no); |
| $crc32 = unpack('N', fread($fp,4))[1]; |
| if ($debug) echo "CRC32 = ".sprintf('0x%08x',$crc32)."\n"; |
| |
| // Get offset (32 bit) |
| fseek($fp, $fanout_offset + 4*256 + 20*$num_objects + 4*$num_objects + 4*$object_no); |
| $offset_info = unpack('N', fread($fp,4))[1]; |
| if ($offset_info >= 0x80000000) { |
| // MSB set, so the offset is 64 bit |
| if ($debug) echo "64 bit pack offset\n"; |
| $offset_info &= 0x7FFFFFFF; |
| fseek($fp, $fanout_offset + 4*256 + 20*$num_objects + 4*$num_objects + 4*$num_objects + 8*$offset_info); |
| $pack_offset = unpack('J', fread($fp,8))[1]; |
| } else { |
| // MSB is not set, so the offset is 32 bit |
| if ($debug) echo "32 bit pack offset\n"; |
| $offset_info &= 0x7FFFFFFF; |
| $pack_offset = $offset_info; |
| } |
| } |
| |
| if ($debug) echo "Pack file offset = ".sprintf('0x%x',$pack_offset)."\n"; |
| |
| // Close index file |
| fclose($fp); |
| |
| // Open pack file |
| $fp = fopen($pack_file, 'rb'); |
| if (!$fp) throw new Exception("Cannot open pack file $pack_file"); |
| |
| // Find out type |
| fseek($fp, $pack_offset); |
| $size_info = unpack('C', fread($fp,1))[1]; |
| |
| $type = ($size_info & 0xE0) >> 5; /*0b11100000*/ |
| switch ($type) { |
| case 1: |
| if ($debug) echo "Type = OBJ_COMMIT ($type)\n"; |
| break; |
| case 2: |
| if ($debug) echo "Type = OBJ_TREE ($type)\n"; |
| break; |
| case 3: |
| if ($debug) echo "Type = OBJ_BLOB ($type)\n"; |
| break; |
| case 4: |
| if ($debug) echo "Type = OBJ_TAG ($type)\n"; |
| break; |
| case 6: |
| if ($debug) echo "Type = OBJ_OFS_DELTA ($type)\n"; |
| break; |
| case 7: |
| if ($debug) echo "Type = OBJ_REF_DELTA ($type)\n"; |
| break; |
| default: |
| if ($debug) echo "Type = Invalid ($type)\n"; |
| break; |
| } |
| |
| // Find out size |
| $size = $size_info & 0x1F /*0x00011111*/; |
| $shift_info = 5; |
| do { |
| $size_info = unpack('C', fread($fp,1))[1]; |
| $size = (($size_info & 0x7F) << $shift_info) + $size; |
| $shift_info += 8; |
| } while ($offset_info >= 0x80000000); |
| |
| if ($debug) echo "Packed size = ".sprintf('0x%x',$size)."\n"; |
| |
| // Read delta base type |
| if ($type == 6/*OBJ_OFS_DELTA*/) { |
| // "a negative relative offset from the delta object's position in the pack |
| // if this is an OBJ_OFS_DELTA object" |
| $delta_info = unpack('C*', fread($fp,4))[1]; // TODO?! |
| if ($debug) echo "Delta negative offset: $delta_info\n"; |
| } |
| if ($type == 7/*OBJ_REF_DELTA*/) { |
| // "base object name if OBJ_REF_DELTA" |
| $delta_info = bin2hex(fread($fp,20))[1]; // TODO?! |
| if ($debug) echo "Delta base object name: $delta_info\n"; |
| } |
| |
| // Read compressed data |
| $compressed = fread($fp,$size); |
| |
| // Uncompress |
| $uncompressed = gzuncompress($compressed); |
| if ($debug) echo "$uncompressed\n"; |
| |
| // Close pack file |
| fclose($fp); |
| |
| // Check CRC32 |
| // TODO: Does not fit, not crc32 nor crc32b... |
| // if ($debug) echo "CRC32 found = 0x".hash('crc32',$compressed)."\n"; |
| |
| return $uncompressed; |
| } |