1 files changed, 154 insertions, 0 deletions
diff --git a/third_party/rust/chardetng_c/include/chardetng.h b/third_party/rust/chardetng_c/include/chardetng.h
new file mode 100644
index 0000000000..b59d05702e
--- /dev/null
+++ b/third_party/rust/chardetng_c/include/chardetng.h
@@ -0,0 +1,154 @@
+// Copyright Mozilla Foundation. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#ifndef chardetng_h
+#define chardetng_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "encoding_rs.h"
+
+#ifndef CHARDETNG_ENCODING_DETECTOR
+#define CHARDETNG_ENCODING_DETECTOR EncodingDetector
+#ifndef __cplusplus
+typedef struct Detector_ EncodingDetector;
+#endif
+#endif
+
+/// Instantiates a Web browser-oriented detector for guessing what
+/// character encoding a stream of bytes is encoded in.
+///
+/// The bytes are fed to the detector incrementally using the
+/// `chardetng_encoding_detector_free` function. The current guess of the
+/// detector can be queried using the `chardetng_encoding_detector_guess`
+/// function. The guessing parameters are arguments to the
+/// `chardetng_encoding_detector_guess` function rather than arguments to the
+/// constructor in order to enable the application to check if the arguments
+/// affect the guessing outcome. (The specific use case is to disable UI for
+/// re-running the detector with UTF-8 allowed and the top-level domain name
+/// ignored if those arguments don't change the guess.)
+///
+/// The instantiated detector must be freed after use using
+/// `chardetng_detectordetector_free`.
+CHARDETNG_ENCODING_DETECTOR* chardetng_encoding_detector_new();
+
+/// Deallocates a detector obtained from `chardetng_encodingdetector_new`.
+void chardetng_encoding_detector_free(CHARDETNG_ENCODING_DETECTOR* detector);
+
+/// Queries whether the TLD is considered non-generic and could affect the guess.
+///
+/// # Undefined Behavior
+///
+/// UB ensues if
+///
+/// * `tld` is non-NULL and `tld_len` is non-zero but `tld` and `tld_len`
+///   don't designate a range of memory valid for reading.
+bool chardetng_encoding_detector_tld_may_affect_guess(char const* tld, size_t tld_len);
+
+/// Inform the detector of a chunk of input.
+///
+/// The byte stream is represented as a sequence of calls to this
+/// function such that the concatenation of the arguments to this
+/// function form the byte stream. It does not matter how the application
+/// chooses to chunk the stream. It is OK to call this function with
+/// a zero-length byte slice.
+///
+/// The end of the stream is indicated by calling this function with
+/// `last` set to `true`. In that case, the end of the stream is
+/// considered to occur after the last byte of the `buffer` (which
+/// may be zero-length) passed in the same call. Once this function
+/// has been called with `last` set to `true` this function must not
+/// be called again.
+///
+/// If you want to perform detection on just the prefix of a longer
+/// stream, do not pass `last=true` after the prefix if the stream
+/// actually still continues.
+///
+/// Returns `true` if after processing `buffer` the stream has
+/// contained at least one non-ASCII byte and `false` if only
+/// ASCII has been seen so far.
+///
+/// # Panics
+///
+/// If this function has previously been called with `last` set to `true`.
+///
+/// # Undefined Behavior
+///
+/// UB ensues if
+///
+/// * `detector` does not point to a detector obtained from
+///   `chardetng_detector_new` but not yet freed with
+///   `chardetng_detector_free`.
+/// * `buffer` is `NULL`. (It can be a bogus pointer when `buffer_len` is 0.)
+/// * ,buffer_len` is non-zero and `buffer` and `buffer_len` don't designate
+///    a range of memory valid for reading.
+bool chardetng_encoding_detector_feed(
+    CHARDETNG_ENCODING_DETECTOR* detector,
+    uint8_t const* buffer,
+    size_t buffer_len,
+    bool last
+);
+
+/// Guess the encoding given the bytes pushed to the detector so far
+/// (via `chardetng_encoding_detector_feed()`), the top-level domain name 
+/// from which the bytes were loaded, and an indication of whether to
+/// consider UTF-8 as a permissible guess.
+///
+/// The `tld` argument takes the rightmost DNS label of the hostname of the
+/// host the stream was loaded from in lower-case ASCII form. That is, if
+/// the label is an internationalized top-level domain name, it must be
+/// provided in its Punycode form. If the TLD that the stream was loaded
+/// from is unavalable, `NULL` may be passed instead (and 0 as `tld_len`),
+/// which is equivalent to passing pointer to "com" as `tld` and 3 as 
+/// `tld_len`.
+///
+/// If the `allow_utf8` argument is set to `false`, the return value of
+/// this function won't be `UTF_8_ENCODING`. When performing detection
+/// on `text/html` on non-`file:` URLs, Web browsers must pass `false`,
+/// unless the user has taken a specific contextual action to request an
+/// override. This way, Web developers cannot start depending on UTF-8
+/// detection. Such reliance would make the Web Platform more brittle.
+///
+/// Returns the guessed encoding (never `NULL`).
+///
+/// # Panics
+///
+/// If `tld` is `NULL` but `tld_len` is not zero.
+///
+/// If `tld` contains non-ASCII, period, or upper-case letters. (The panic
+/// condition is intentionally limited to signs of failing to extract the
+/// label correctly, failing to provide it in its Punycode form, and failure
+/// to lower-case it. Full DNS label validation is intentionally not performed
+/// to avoid panics when the reality doesn't match the specs.)
+///
+/// # Undefined Behavior
+///
+/// UB ensues if
+///
+/// * `detector` does not point to a detector obtained from
+///   `chardetng_detector_new` but not yet freed with
+///   `chardetng_detector_free`.
+/// * `tld` is non-NULL and `tld_len` is non-zero but `tld` and `tld_len`
+///   don't designate a range of memory valid for reading.
+ENCODING_RS_ENCODING const* chardetng_encoding_detector_guess(
+    CHARDETNG_ENCODING_DETECTOR const* detector,
+    char const* tld,
+    size_t tld_len,
+    bool allow_utf8
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // chardetng_h