Merge lp:~jelmer/brz/serializer-xml-1 into lp:brz

[Jelmer Vernooij]

Move some xml helper functions to rust

Move some xml helper functions to rust

[Jelmer Vernooij (jelmer)]

review: Approve

=== modified file 'breezy/bzr/tests/test_xml.py'
--- breezy/bzr/tests/test_xml.py	2023-04-30 20:58:50 +0000
+++ breezy/bzr/tests/test_xml.py	2023-05-05 15:54:42 +0000
@@ -528,21 +528,14 @@
 class TestEncodeAndEscape(TestCase):
     """Whitebox testing of the _encode_and_escape function."""
 
-    def setUp(self):
-        super().setUp()
-        # Keep the cache clear before and after the test
-        breezy.bzr.xml_serializer._clear_cache()
-        self.addCleanup(breezy.bzr.xml_serializer._clear_cache)
-
     def test_simple_ascii(self):
         # _encode_and_escape always appends a final ", because these parameters
         # are being used in xml attributes, and by returning it now, we have to
         # do fewer string operations later.
         val = breezy.bzr.xml_serializer.encode_and_escape('foo bar')
         self.assertEqual(b'foo bar', val)
-        # The second time should be cached
         val2 = breezy.bzr.xml_serializer.encode_and_escape('foo bar')
-        self.assertIs(val2, val)
+        self.assertEqual(val2, val)
 
     def test_ascii_with_xml(self):
         self.assertEqual(b'&'"<>',
 
=== modified file 'breezy/bzr/xml_serializer.py'
--- breezy/bzr/xml_serializer.py	2023-05-03 17:01:16 +0000
+++ breezy/bzr/xml_serializer.py	2023-05-05 15:54:42 +0000
@@ -100,24 +100,6 @@
         return ElementTree().parse(f)
 
 
-def escape_invalid_chars(message):
-    """Escape the XML-invalid characters in a commit message.
-
-    :param message: Commit message to escape
-    :return: tuple with escaped message and number of characters escaped
-    """
-    if message is None:
-        return None, 0
-    # Python strings can include characters that can't be
-    # represented in well-formed XML; escape characters that
-    # aren't listed in the XML specification
-    # (http://www.w3.org/TR/REC-xml/#NT-Char).
-    return re.subn('[^\x09\x0A\x0D\u0020-\uD7FF\uE000-\uFFFD]+',
-                   lambda match: match.group(0).encode(
-                       'unicode_escape').decode('ascii'),
-                   message)
-
-
 def get_utf8_or_ascii(a_str):
     """Return a cached version of the string.
 
@@ -139,84 +121,7 @@
         return a_str
 
 
-_utf8_re = lazy_regex.lazy_compile(b'[&<>\'\"]|[\x80-\xff]+')
-_unicode_re = lazy_regex.lazy_compile('[&<>\'\"\u0080-\uffff]')
-
-
-_xml_escape_map = {
-    "&": '&amp;',
-    "'": "&apos;",  # FIXME: overkill
-    "\"": "&quot;",
-    "<": "&lt;",
-    ">": "&gt;",
-    }
-
-
-def _unicode_escape_replace(match, _map=_xml_escape_map):
-    """Replace a string of non-ascii, non XML safe characters with their escape
-
-    This will escape both Standard XML escapes, like <>"', etc.
-    As well as escaping non ascii characters, because ElementTree did.
-    This helps us remain compatible to older versions of bzr. We may change
-    our policy in the future, though.
-    """
-    # jam 20060816 Benchmarks show that try/KeyError is faster if you
-    # expect the entity to rarely miss. There is about a 10% difference
-    # in overall time. But if you miss frequently, then if None is much
-    # faster. For our use case, we *rarely* have a revision id, file id
-    # or path name that is unicode. So use try/KeyError.
-    try:
-        return _map[match.group()]
-    except KeyError:
-        return "&#%d;" % ord(match.group())
-
-
-def _utf8_escape_replace(match, _map=_xml_escape_map):
-    """Escape utf8 characters into XML safe ones.
-
-    This uses 2 tricks. It is either escaping "standard" characters, like "&<>,
-    or it is handling characters with the high-bit set. For ascii characters,
-    we just lookup the replacement in the dictionary. For everything else, we
-    decode back into Unicode, and then use the XML escape code.
-    """
-    try:
-        return _map[match.group().decode('ascii', 'replace')].encode()
-    except KeyError:
-        return b''.join(b'&#%d;' % ord(uni_chr)
-                        for uni_chr in match.group().decode('utf8'))
-
-
-_to_escaped_map: Dict[Union[bytes, str], str] = {}
-
-
-def encode_and_escape(unicode_or_utf8_str, _map=_to_escaped_map):
-    """Encode the string into utf8, and escape invalid XML characters"""
-    # We frequently get entities we have not seen before, so it is better
-    # to check if None, rather than try/KeyError
-    text = _map.get(unicode_or_utf8_str)
-    if text is None:
-        if isinstance(unicode_or_utf8_str, str):
-            # The alternative policy is to do a regular UTF8 encoding
-            # and then escape only XML meta characters.
-            # Performance is equivalent once you use codecs. *However*
-            # this makes the serialized texts incompatible with old versions
-            # of bzr. So no net gain. (Perhaps the read code would handle utf8
-            # better than entity escapes, but cElementTree seems to do just
-            # fine either way)
-            text = _unicode_re.sub(
-                _unicode_escape_replace, unicode_or_utf8_str).encode()
-        else:
-            # Plain strings are considered to already be in utf-8 so we do a
-            # slightly different method for escaping.
-            text = _utf8_re.sub(_utf8_escape_replace,
-                                unicode_or_utf8_str)
-        _map[unicode_or_utf8_str] = text
-    return text
-
-
-def _clear_cache():
-    """Clean out the unicode => escaped map"""
-    _to_escaped_map.clear()
+from .._bzr_rs import encode_and_escape, escape_invalid_chars
 
 
 def unpack_inventory_entry(elt, entry_cache=None, return_from_cache=False):
 
=== modified file 'crates/bazaar-py/src/lib.rs'
--- crates/bazaar-py/src/lib.rs	2023-05-05 12:17:33 +0000
+++ crates/bazaar-py/src/lib.rs	2023-05-05 15:54:42 +0000
@@ -4,7 +4,7 @@
 use pyo3::exceptions::{PyNotImplementedError, PyRuntimeError, PyTypeError, PyValueError};
 use pyo3::import_exception;
 use pyo3::prelude::*;
-use pyo3::types::{PyBytes, PyList, PyString};
+use pyo3::types::{PyBytes, PyList, PyString, PyUnicode};
 use pyo3_file::PyFileLikeObject;
 use std::collections::HashMap;
 
@@ -402,6 +402,28 @@
     }
 }
 
+#[pyfunction]
+fn escape_invalid_chars(message: Option<&str>) -> (Option<String>, usize) {
+    bazaar::xml_serializer::escape_invalid_chars(message)
+}
+
+#[pyfunction]
+fn encode_and_escape(py: Python, unicode_or_utf8_str: PyObject) -> PyResult<&PyBytes> {
+    if let Ok(text) = unicode_or_utf8_str.extract::<&str>(py) {
+        Ok(PyBytes::new(
+            py,
+            bazaar::xml_serializer::encode_and_escape_string(text).as_slice(),
+        ))
+    } else if let Ok(bytes) = unicode_or_utf8_str.extract::<&[u8]>(py) {
+        Ok(PyBytes::new(
+            py,
+            bazaar::xml_serializer::encode_and_escape_bytes(bytes).as_slice(),
+        ))
+    } else {
+        Err(PyTypeError::new_err("expected str or bytes"))
+    }
+}
+
 #[pymodule]
 fn _bzr_rs(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_wrapped(wrap_pyfunction!(_next_id_suffix))?;
@@ -424,5 +446,7 @@
     m.add_wrapped(wrap_pyfunction!(is_null_revision))?;
     m.add_wrapped(wrap_pyfunction!(is_reserved_revision_id))?;
     m.add_wrapped(wrap_pyfunction!(check_not_reserved_id))?;
+    m.add_wrapped(wrap_pyfunction!(escape_invalid_chars))?;
+    m.add_wrapped(wrap_pyfunction!(encode_and_escape))?;
     Ok(())
 }
 
=== modified file 'crates/bazaar/src/globbing.rs'
--- crates/bazaar/src/globbing.rs	2023-04-22 02:01:38 +0000
+++ crates/bazaar/src/globbing.rs	2023-05-05 15:54:42 +0000
@@ -31,6 +31,8 @@
     Closure(Box<dyn FnMut(String) -> String + Sync + Send>),
 }
 
+// TODO(jelmer): Consider using RegexSet from the regex crate instead.
+
 /// Do a multiple-pattern substitution.
 ///
 /// The patterns and substitutions are combined into one, so the result of
 
=== modified file 'crates/bazaar/src/lib.rs'
--- crates/bazaar/src/lib.rs	2023-05-05 12:14:36 +0000
+++ crates/bazaar/src/lib.rs	2023-05-05 15:54:42 +0000
@@ -94,3 +94,4 @@
 }
 
 pub mod bencode_serializer;
+pub mod xml_serializer;
 
=== added file 'crates/bazaar/src/xml_serializer.rs'
--- crates/bazaar/src/xml_serializer.rs	1970-01-01 00:00:00 +0000
+++ crates/bazaar/src/xml_serializer.rs	2023-05-05 15:54:42 +0000
@@ -0,0 +1,81 @@
+use std::str;
+
+lazy_static::lazy_static! {
+    static ref UTF8_RE: regex::bytes::Regex = regex::bytes::Regex::new(r#"(?-u)[&<>'"]|[\x80-\xff]+"#).unwrap();
+    static ref UNICODE_RE: regex::Regex = regex::Regex::new(r#"[&<>'"\u{0080}-\u{ffff}]"#).unwrap();
+
+}
+
+fn escape_low(c: u8) -> Option<&'static str> {
+    match c {
+        b'&' => Some("&amp;"),
+        b'\'' => Some("&apos;"),
+        b'"' => Some("&quot;"),
+        b'<' => Some("&lt;"),
+        b'>' => Some("&gt;"),
+        _ => None,
+    }
+}
+
+fn unicode_escape_replace(cap: &regex::Captures) -> String {
+    let m = cap.get(0).unwrap();
+    assert_eq!(m.as_str().chars().count(), 1,);
+    let c = m.as_str().chars().next().unwrap();
+    if m.len() == 1 {
+        if let Some(ret) = escape_low(m.as_str().as_bytes()[0]) {
+            return ret.to_string();
+        }
+    }
+    format!("&#{};", c as u32)
+}
+
+fn utf8_escape_replace(cap: &regex::bytes::Captures) -> Vec<u8> {
+    let m = cap.get(0).unwrap().as_bytes();
+    eprintln!("m: {:?}", cap);
+    if m.len() == 1 {
+        if let Some(ret) = escape_low(m[0]) {
+            return ret.as_bytes().to_vec();
+        }
+    }
+    let utf8 = str::from_utf8(m).unwrap();
+    utf8.chars()
+        .map(|c| format!("&#{};", c as u64).into_bytes())
+        .collect::<Vec<Vec<u8>>>()
+        .concat()
+}
+
+pub fn encode_and_escape_string(text: &str) -> Vec<u8> {
+    UNICODE_RE
+        .replace_all(text, unicode_escape_replace)
+        .as_bytes()
+        .to_vec()
+}
+
+pub fn encode_and_escape_bytes(data: &[u8]) -> Vec<u8> {
+    UTF8_RE.replace_all(data, utf8_escape_replace).to_vec()
+}
+
+pub fn escape_invalid_chars(message: Option<&str>) -> (Option<String>, usize) {
+    if let Some(msg) = message {
+        let escaped = msg
+            .chars()
+            .map(|c| {
+                if c == '\t' || c == '\n' || c == '\r' || c == '\x7f' {
+                    c.to_string()
+                } else if c.is_ascii_control()
+                    || (c as u32) > 0xD7FF && (c as u32) < 0xE000
+                    || (c as u32) > 0xFFFD && (c as u32) < 0x10000
+                {
+                    format!("\\x{:02x}", c as u32)
+                } else {
+                    c.to_string()
+                }
+            })
+            .collect::<Vec<String>>()
+            .join("");
+
+        (Some(escaped), msg.len())
+    } else {
+        (None, 0)
+    }
+}