1 files changed, 383 insertions, 0 deletions
diff --git a/patchstate.py b/patchstate.py
new file mode 100644
index 0000000..79600e0
--- /dev/null
+++ b/patchstate.py
@@ -0,0 +1,383 @@
+import io, sys, os, operator, re, base64, hashlib
+import patchtheory
+
+def strip_subject(s):
+    if not s.startswith(b'[PATCH'):
+        raise ValueError(f'Invalid subject: {s!r}')
+    i = s.find(b'] ')
+    if i == -1:
+        raise ValueError(f'Invalid subject: {s!r}')
+    return s[i+2:]
+
+rem_patch = re.compile('patch ([0-9a-z]{16})').fullmatch
+rem_author = re.compile('[^\0-\x1f]+ <[^\0-\x1f]+@[^\0-\x1f]+>').fullmatch
+rem_date = re.compile('[^\0-\x1f]+').fullmatch
+rem_title = re.compile('[^\0-\x1f]+').fullmatch
+
+class Patch:
+    __slots__ = ('author', 'date', 'title', 'body', 'diff', 'data', 'hash', 'id')
+
+    def __init__(self, /, *, author, date, title, body, diff):
+        assert type(author) is str and rem_author(author) is not None
+        assert type(date) is str and rem_date(date) is not None
+        assert type(title) is str and rem_title(title) is not None
+        assert type(body) is str
+        assert type(diff) is patchtheory.Diff
+
+        self.author = author
+        self.date = date
+        self.title = title
+        self.body = body
+        self.diff = diff
+
+        self._set_data()
+        self._set_id()
+
+    @classmethod
+    def parse(tp, body):
+        lines = iter(body.split(b'\n'))
+        line = lines.__next__
+
+        l = line()
+        if l.startswith(b'From '):
+            l = line()
+
+        headers = {}
+        hdr = None
+        while True:
+            if not l:
+                break
+            if hdr is not None and l.startswith(b' '):
+                headers[hdr] += l
+            else:
+                hdr,sep,val = l.partition(b':')
+                if not sep:
+                    raise ValueError(f'Expected header line: {l!r}')
+                headers[hdr] = val.lstrip()
+            l = line()
+
+        author = headers.pop(b'From').decode('utf-8')
+        date = headers.pop(b'Date').decode('utf-8')
+        title = strip_subject(headers.pop(b'Subject')).decode('utf-8')
+
+        headers.pop(b'MIME-Version', None)
+        headers.pop(b'Content-Type', None)
+        headers.pop(b'Content-Transfer-Encoding', None)
+
+        body = []
+        for l in lines:
+            if l.startswith(b'diff --git'):
+                break
+            body.append(l)
+        else:
+            raise RuntimeError('unexpected EOF')
+        while not body[-1]:
+            del body[-1]
+        while body[-1].startswith(b' '):
+            del body[-1]
+        if body[-1] != b'---':
+            raise RuntimeError
+        del body[-1]
+        while body and not body[-1]:
+            del body[-1]
+
+        body = b'\n'.join(body).decode('utf-8')
+
+        return Patch(
+            author = author,
+            date = date,
+            title = title,
+            body = body,
+            diff = patchtheory.Diff.parse_l(l, line),
+        )
+
+    def _set_id(self):
+        out = io.BytesIO()
+        w = out.write
+        w(self.author.encode('utf-8'))
+        w(b'\n')
+        w(self.date.encode('utf-8'))
+        w(b'\n')
+        w(self.title.encode('utf-8'))
+        w(b'\n')
+        self.diff.write_munged(w)
+
+        out = out.getvalue()
+        dgst = hashlib.blake2b(out).digest()
+        self.id = base64.b32encode(dgst[:10]).lower().decode('ascii')
+
+    def as_filename(self):
+        return '-'.join(re.findall('[0-9A-Za-z]+', self.title))[:72]
+
+    def _set_data(self):
+        out = io.BytesIO()
+        w = out.write
+
+        w(b'From: ')
+        w(self.author.encode('utf-8'))
+        w(b'\nDate: ')
+        w(self.date.encode('utf-8'))
+        w(b'\nSubject: [PATCH] ')
+        w(self.title.encode('utf-8'))
+        w(b'\n\n')
+        w(self.body.encode('utf-8'))
+        w(b'\n---\n\n')
+        self.diff.write(w)
+        w(b'-- \n0.0.0 patchstate\n\n')
+
+        self.data = data = out.getvalue()
+
+        self.hash = base64.b32encode(hashlib.blake2b(data).digest()[:20]).lower().decode('ascii')
+
+    def revert(self):
+        r = Patch(
+            author = self.author,
+            date = self.date,
+            title = f'Revert "{self.title}"',
+            body = self.body,
+            diff = -self.diff,
+        )
+
+        r._set_data()
+        r._set_id()
+        return r
+
+class PatchInfo:
+    __slots__ = ('patch_id', '_body')
+
+    def __init__(self, patch_id, info):
+        self.patch_id = patch_id
+        self._body = info
+
+    def get_patch(self, repo):
+        p = repo.patches[self.patch_hash]
+        if p.id != self.patch_id:
+            raise KeyError(f'patch id mismatch: {self.patch_id!r} -> {p.id!r}')
+        if p.title != self.patch_title:
+            raise KeyError(f'patch title mismatch: {self.patch_title!r} -> {p.title!r}')
+        return p
+
+    @property
+    def patch_hash(self):
+        return self._body[0]
+
+    @property
+    def patch_title(self):
+        return self._body[1]
+
+    @property
+    def mode(self):
+        return self._body[2]
+
+    @property
+    def info(self):
+        return self._body[3:]
+
+    def update(self, *, patch=None, patch_id=None, patch_hash=None, patch_title=None, mode=None, new_mode=None, info=None):
+        if patch_title is None:
+            patch_title = self.patch_title
+
+        if patch is not None:
+            assert patch_id is None
+            assert patch_hash is None
+            if patch_title != patch.title:
+                raise ValueError('patch title change: {patch_title!r} -> {patch.title!r}')
+            patch_id = patch.id
+            patch_hash = patch.hash
+
+        else:
+            if patch_id is None:
+                patch_id = self.patch_id
+
+            if patch_hash is None:
+                patch_hash = self.patch_hash
+
+        if info is None:
+            info = self.info
+
+        if mode is None:
+            mode = self.mode
+
+        if new_mode is not None and new_mode != mode:
+            info.insert(0, f'(was {mode})')
+            mode = new_mode
+
+        return PatchInfo(patch_id, [patch_hash, patch_title, mode, *info])
+
+class Series:
+    __slots__ = ('info',)
+
+    def __init__(self, /, info=None):
+        if info is None:
+            info = []
+        self.info = info
+
+    @classmethod
+    def parse(tp, data):
+        inf = []
+
+        lines = iter(data.split('\n'))
+        l = next(lines)
+        while True:
+            if not l:
+                try:
+                    l = next(lines)
+                except StopIteration:
+                    break
+                continue
+            m = rem_patch(l)
+            if m is None:
+                raise ValueError(f'Invalid header: {l!r}')
+            pid = m.group(1)
+            ldata = []
+            while True:
+                l = next(lines)
+                if not l.startswith('\t'):
+                    break
+                ldata.append(l[1:])
+            if len(ldata) < 3:
+                raise ValueError(f'Expected data after {f"patch {pid}"!r}')
+
+            while ldata and not ldata[-1]:
+                del ldata[-1]
+
+            inf.append(PatchInfo(pid, ldata))
+
+        return tp(info=inf)
+
+    def fmt(self):
+        out = io.StringIO()
+        w = out.write
+
+        for pi in self.info:
+            w(f'patch {pi.patch_id}')
+            for line in pi._body:
+                w('\n\t')
+                w(line)
+            w('\n')
+
+        return out.getvalue()
+
+class Repository:
+    __slots__ = ('path', 'patches', 'aliases', 'by_id')
+
+    def __init__(self, path):
+        self.path = path
+        self.patches = {}
+        self.by_id = {}
+
+        aliases = {}
+        for fn in os.listdir(path):
+            if not fn.endswith('.patch'):
+                continue
+            fp = os.path.join(path, fn)
+            with io.open(fp, 'rb') as f:
+                data = f.read()
+
+            try:
+                p = Patch.parse(data)
+            except ValueError as exc:
+                print(f'Failed to parse {fn!r}: {exc}', file=sys.stderr)
+                os.unlink(fp)
+                continue
+
+            h = p.hash
+            if fn != f'{h}.patch':
+                aliases[fn[:-6]] = (h,p)
+            else:
+                self.patches[h] = p
+            self.by_id.setdefault(p.id, []).append(p)
+
+        for h,(h2,p) in aliases.items():
+            assert h != h2
+            assert h not in self.patches
+            if h2 in self.patches:
+                continue
+            print(f'Migrating patch: {h!r} -> {h2!r}', file=sys.stderr)
+            self.patches[h2] = p
+            with io.open(os.path.join(self.path, f'{h2}.patch'), 'xb') as f:
+                f.write(p.data)
+
+        self.aliases = {h: h2 for h,(h2,p) in aliases.items()}
+
+    def hash_data(self, data):
+        data = hashlib.blake2b(data).digest()
+        return base64.b32encode(data[:20]).lower().decode()
+
+    def insert_patch(self, patch):
+        p = self.patches.setdefault(patch.hash, patch)
+        if p is patch:
+            pid = p.id
+            try:
+                pd = self.by_id[pid]
+            except KeyError:
+                self.by_id[pid] = [p]
+            else:
+                print(f'Duplicate patch ID: {pid!r} {p.title}', file=sys.stderr)
+                pd.append(p)
+
+            with io.open(os.path.join(self.path, f'{p.hash}.patch'), 'xb') as f:
+                f.write(p.data)
+
+        return p
+
+    def import_dir(self, path):
+        r = Series()
+        r.info = inf = []
+
+        for fn in sorted(os.listdir(path)):
+            if not fn.endswith('.patch'):
+                print(f'Skipping {fn!r}', file=sys.stderr)
+                continue
+            with io.open(os.path.join(path, fn), 'rb') as f:
+                patch = Patch.parse(f.read())
+
+            patch = self.insert_patch(patch)
+            inf.append(PatchInfo(patch.id, [patch.hash, patch.title, 'new']))
+
+        return r
+
+    def gc(self, keep):
+        for h in self.patches.keys() - keep:
+            del self.patches[h]
+            print(f'Removing patch: {h!r}', file=sys.stderr)
+            os.unlink(os.path.join(self.path, f'{h}.patch'))
+
+def argparse_next(args, func=...):
+    def do_argparse(func):
+        while True:
+            try:
+                arg = next(args)
+            except StopIteration:
+                return None
+            if arg == '--':
+                return next(args, None)
+            if not arg.startswith('-'):
+                return arg
+            arg = func(arg)
+            if arg is not None:
+                return arg
+    if func is not ...:
+        return do_argparse(func)
+    return do_argparse
+
+def argparse_all(args, func=...):
+    def do_argparse(func):
+        r = []
+        while True:
+            try:
+                arg = next(args)
+            except StopIteration:
+                return r
+            if arg == '--':
+                r.extend(args)
+                return r
+            if not arg.startswith('-'):
+                r.append(arg)
+                continue
+            arg = func(arg)
+            if arg is not None:
+                r.extend(arg)
+    if func is not ...:
+        return do_argparse(func)
+    return do_argparse