Import upstream v0.16.22, stripped

Upstream commit: 474dd0229cb20cf513036619781ed97bd8073c3f Enterprise-only files removed or emptied: 63 Enterprise-only snippets removed: 117 in 50 files Dangling module declarations removed: 5 Cargo edits turning enterprise off: 14 Verification: clean Enterprise feature gates left for rebuilt features: 19 in 18 files Produced by tools/fork/strip.py. The full report is in docs/fork/strip-reports/ on main.
2026-09-18 10:21:56 -07:00
commit 7dae9b29fd
1650 changed files with 485521 additions and 0 deletions
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+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+use std::borrow::Cow;
+
+enum State {
+    Len {
+        buf: [u8; std::mem::size_of::<u32>()],
+        bytes_read: usize,
+    },
+    Frame {
+        buf: Vec<u8>,
+        frame_len: usize,
+    },
+}
+
+pub struct Receiver {
+    packet_pos: usize,
+    state: State,
+    max_frame_len: usize,
+}
+
+pub enum FrameResult<'x> {
+    Frame(Cow<'x, [u8]>),
+    Incomplete,
+    TooLarge(usize),
+}
+
+impl Default for State {
+    fn default() -> Self {
+        State::Len {
+            buf: [0; std::mem::size_of::<u32>()],
+            bytes_read: 0,
+        }
+    }
+}
+
+impl Receiver {
+    pub fn with_max_frame_len(max_frame_len: usize) -> Self {
+        Receiver {
+            packet_pos: 0,
+            state: State::default(),
+            max_frame_len,
+        }
+    }
+
+    pub fn read_frame<'x>(&mut self, packet: &'x [u8]) -> FrameResult<'x> {
+        if !packet.is_empty() {
+            match &mut self.state {
+                State::Len { buf, bytes_read } => {
+                    while *bytes_read < std::mem::size_of::<u32>() {
+                        if let Some(byte) = packet.get(self.packet_pos) {
+                            buf[*bytes_read] = *byte;
+                            *bytes_read += 1;
+                            self.packet_pos += 1;
+                        } else {
+                            self.packet_pos = 0;
+                            return FrameResult::Incomplete;
+                        }
+                    }
+                    let length = u32::from_be_bytes(*buf) as usize;
+                    if length <= self.max_frame_len {
+                        if let Some(frame) = packet.get(self.packet_pos..self.packet_pos + length) {
+                            self.packet_pos += length;
+                            self.state = State::default();
+                            FrameResult::Frame(frame.into())
+                        } else {
+                            let mut buf = Vec::with_capacity(length);
+                            if let Some(bytes_available) = packet.get(self.packet_pos..) {
+                                buf.extend(bytes_available);
+                            }
+                            self.state = State::Frame {
+                                buf,
+                                frame_len: length,
+                            };
+                            self.packet_pos = 0;
+                            FrameResult::Incomplete
+                        }
+                    } else {
+                        FrameResult::TooLarge(length)
+                    }
+                }
+                State::Frame { buf, frame_len } => {
+                    let bytes_pending = *frame_len - buf.len();
+                    if let Some(bytes) =
+                        packet.get(self.packet_pos..self.packet_pos + bytes_pending)
+                    {
+                        let mut buf = std::mem::take(buf);
+                        buf.extend(bytes);
+                        self.packet_pos += bytes_pending;
+                        self.state = State::default();
+                        FrameResult::Frame(buf.into())
+                    } else if let Some(bytes_available) = packet.get(self.packet_pos..) {
+                        buf.extend(bytes_available);
+                        self.packet_pos = 0;
+                        FrameResult::Incomplete
+                    } else {
+                        self.packet_pos = 0;
+                        FrameResult::Incomplete
+                    }
+                }
+            }
+        } else {
+            FrameResult::Incomplete
+        }
+    }
+}