Added util.py

Provide a bunch of utilities for soypak.

Specify compiled regexes for bottle file parsing.

func@ensure_dir:
	- Will ensure that a directory that exists, and if it doesn't, will
	  create it and any parents. Mode is 0755.
	- From DNF util module.

func@join_path:
	- Will join any number of string paths together and return a new
	  string path.
	- From eopkg util module.

func@rack_bottle:
	- Function will aim to write a new bottle file out to the database
	  (nickname: rack).
	- Either a string representation of a bottle file can be given, or a
	  file descriptor of type TextIOWrapper, can be given as the file
	  pointer:
		- if a TextIOWrapper, ensure that the pointer is at the start of
		  the file to read the contents again.
		- if a string, the contents can be set at this.
	- Detect if there are any comments (useful from translating user
	  defined bottles to be stored - Packages file won't have this). If
	  so, remove them.
	- Ensure that the database rack exists.
	- Create the new filename to be stored.
	- Attempt to open the file in write mode and write the contents to
	  file. Report on the amount of bytes written for clarity.
	- Function returns true if the file was successfully racked. False
	  upon any failures.

soypak/util.py

@@ -0,0 +1,85 @@
+import os
+import re
+import clog
+import errno
+import soypak.db
+from io import TextIOWrapper
+
+
+_log = clog.Logger.get("runtime_logger")
+
+
+re_comments = re.compile(r"(--.*$|\*--(\n.*?)+--\*)", re.MULTILINE)
+re_desc_tag = re.compile(r"^Description:(?: .*\n)+", re.MULTILINE)
+
+
+# from DNF util module (https://github.com/rpm-software-management/dnf/blob/master/dnf/util.py#L142)
+def ensure_dir(dname) -> tuple[int, str]:
+    try:
+        os.makedirs(dname, mode=0o755)
+    except OSError as err:
+        if err.errno != errno.EEXIST or not os.path.isdir(dname):
+            return err.errno, str(err)
+
+    return 0, ""
+
+
+# from eopkg util module (https://github.com/solus-project/package-management/blob/master/pisi/util.py#L293)
+def join_path(a, *p) -> str:
+    """Join two or more pathname components.
+    Python os.path.join cannot handle '/' at the start of latter components.
+    """
+    for b in p:
+        b = b.lstrip('/')
+        if a == '' or a.endswith('/'):
+            a += b
+            continue
+        a += '/' + b
+    return a
+
+
+def rack_bottle(fp: TextIOWrapper | str, f_name: str) -> bool:
+    """Store a bottle file in the database and update package cache."""
+    if isinstance(fp, TextIOWrapper):
+        _log.debug(f"{fp=}, ensuring file is read from beginning...", end="")
+        try:
+            # ensure we are at the start of the file before reading
+            fp.seek(0)
+            c = fp.read()
+        except IOError as err:
+            _log.writeLog("failed.")
+            _log.error(f"Couldn't open file for reading: {str(err)}")
+            return False
+        finally:
+            _log.writeLog("ok.")
+            fp.close()
+
+        f_name = fp.name.split('/')[-1]
+    else:
+        _log.debug("fp is a string. The contents can be directly used.")
+        c = fp
+
+    # clean the file of any comments (specific to storing from user input)
+    if re.search(re_desc_tag, c):
+        _log.debug("Scrubbing bottle comments from string content.")
+        c = re.sub(re_desc_tag, "", c)
+
+    result = ensure_dir(soypak.db.rack_db_dir)
+    if result[0] != 0:
+        _log.error(f"There was an issue when ensuring directory (exit code: {result[0]}): {result[1]}")
+        return False
+
+    new_file = join_path(soypak.db.rack_db_dir, f_name)
+    _log.debug(f"Opening new file to write bottle file to permanently: {new_file!r}")
+    try:
+        fp = open(new_file, 'w')
+    except IOError as err:
+        _log.error(f"There was an issue attempting to write to {new_file!r}: {str(err)}")
+        return False
+
+    fp.write(c)
+    s = fp.tell()
+    fp.close()
+
+    _log.debug("Successfully wrote %s bytes to file." % s)
+    return True