Rebuild local files from pristine SVN

rebuild.py

#
# This is roughly equivalent to `svn export`
# Useful when you have a .svn directory but are unable to reach the SVN
# repository that it came from (e.g. a network-based one)
# If you have /tmp/someworking/.svn:
#   $ python rebuild.py /tmp/someworking /tmp/rebuilt
# That will unpack all of the pristine files into /tmp/rebuilt
#
# mzpqnxow (by way of LLMs, with a few minor fixes)
#
import os
import sqlite3
import shutil

def rebuild_working_copy(wc_path: str) -> None:
    """
    Rebuilds the working copy from the .svn metadata.

    Args:
        wc_path: The root directory of your working copy (the directory that contains the .svn folder).
    """
    svn_dir = os.path.join(wc_path, ".svn")
    db_path = os.path.join(svn_dir, "wc.db")
    pristine_path = os.path.join(svn_dir, "pristine")

    if not os.path.exists(db_path):
        print("wc.db not found. Is this a valid SVN working copy?")
        return

    # Connect to the wc.db SQLite database.
    conn = sqlite3.connect(db_path)
    cursor = conn.cursor()

    # In SVN 1.7 and later, the NODES table holds the metadata.
    # We'll select all items at the base layer (op_depth = 0) to get the original state.
    cursor.execute("SELECT local_relpath, checksum, kind FROM NODES WHERE op_depth = 0")
    rows = cursor.fetchall()

    for local_relpath, checksum, kind in rows:
        # Build the target path in the working copy.
        target_path = os.path.join(wc_path, local_relpath)

        if kind == "dir":
            # Create the directory if it doesn't exist.
            if not os.path.exists(target_path):
                os.makedirs(target_path)
                print(f"Created directory: {target_path}")
        elif kind == "file":
            # Files are stored in the pristine store.
            # The checksum is stored as "sha1-<hash>".
            if checksum.startswith("sha1-"):
                hash_val = checksum[5:]
            elif checksum.startswith("$sha1$"):
                hash_val = checksum[6:]
            else:
                hash_val = checksum

            # The file is located under .svn/pristine/<first two hash chars>/<hash_val>.svn-base
            # subdir = hash_val[6:]
            subdir = hash_val[0:2]
            pristine_file = os.path.join(pristine_path, subdir, f"{hash_val}.svn-base")

            if os.path.exists(pristine_file):
                # Make sure the target directory exists.
                os.makedirs(os.path.dirname(target_path), exist_ok=True)
                shutil.copy2(pristine_file, target_path)
                print(f"Recovered file: {target_path}")
            else:
                print(f"WARNING: Pristine file not found for {target_path} (expected at {pristine_file})")
        else:
            print(f"Unknown item kind: {kind} for path: {local_relpath}")

    conn.close()

if __name__ == '__main__':
    # Change this path to the root of your working copy
    working_copy_path = "./"
    rebuild_working_copy(working_copy_path)