| // Protocol Buffers - Google's data interchange format |
| // Copyright 2024 Google LLC. All rights reserved. |
| // |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file or at |
| // https://developers.google.com/open-source/licenses/bsd |
| |
| use crate::{upb_MiniTable, RawMessage}; |
| |
| extern "C" { |
| /// Returns the minimum needed length (excluding NULL) that `buf` has to be |
| /// to hold the `msg`s debug string. |
| /// |
| /// SAFETY: |
| /// - `msg` is pointing at a valid upb_Message with associated minitable |
| /// `mt` |
| /// - `buf` is legally writable for `size` bytes (`buf` may be nullptr if |
| /// `size` is 0) |
| fn upb_DebugString( |
| msg: RawMessage, |
| mt: *const upb_MiniTable, |
| options: i32, |
| buf: *mut u8, |
| size: usize, |
| ) -> usize; |
| } |
| |
| #[allow(dead_code)] |
| #[repr(i32)] |
| enum Options { |
| // When set, prints everything on a single line. |
| SingleLine = 1, |
| |
| // When set, unknown fields are not printed. |
| SkipUnknown = 2, |
| |
| // When set, maps are *not* sorted (this avoids allocating tmp mem). |
| NoSortMaps = 4, |
| } |
| |
| /// Returns a string of field number to value entries of a message. |
| /// |
| /// # Safety |
| /// - `mt` must correspond to the `msg`s minitable. |
| pub unsafe fn debug_string(msg: RawMessage, mt: *const upb_MiniTable) -> String { |
| // Only find out the length first to then allocate a buffer of the minimum size |
| // needed. |
| // SAFETY: |
| // - `msg` is a legally dereferencable upb_Message whose associated minitable is |
| // `mt` |
| // - `buf` is nullptr and `buf_len` is 0 |
| let len = |
| unsafe { upb_DebugString(msg, mt, Options::NoSortMaps as i32, std::ptr::null_mut(), 0) }; |
| assert!(len < isize::MAX as usize); |
| // +1 for the trailing NULL |
| let mut buf = vec![0u8; len + 1]; |
| // SAFETY: |
| // - `msg` is a legally dereferencable upb_Message whose associated minitable is |
| // `mt` |
| // - `buf` is legally writable for 'buf_len' bytes |
| let written_len = unsafe { |
| upb_DebugString(msg, mt, Options::NoSortMaps as i32, buf.as_mut_ptr(), buf.len()) |
| }; |
| assert_eq!(len, written_len); |
| String::from_utf8_lossy(buf.as_slice()).to_string() |
| } |