| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/base64-0.21.2/src/write/encoder.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>encoder.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../base64/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../base64/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span><span class="kw">crate</span>::engine::Engine; |
| <span class="kw">use </span>std::{ |
| cmp, fmt, io, |
| io::{ErrorKind, <span class="prelude-ty">Result</span>}, |
| }; |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">const </span>BUF_SIZE: usize = <span class="number">1024</span>; |
| <span class="doccomment">/// The most bytes whose encoding will fit in `BUF_SIZE` |
| </span><span class="kw">const </span>MAX_INPUT_LEN: usize = BUF_SIZE / <span class="number">4 </span>* <span class="number">3</span>; |
| <span class="comment">// 3 bytes of input = 4 bytes of base64, always (because we don't allow line wrapping) |
| </span><span class="kw">const </span>MIN_ENCODE_CHUNK_SIZE: usize = <span class="number">3</span>; |
| |
| <span class="doccomment">/// A `Write` implementation that base64 encodes data before delegating to the wrapped writer. |
| /// |
| /// Because base64 has special handling for the end of the input data (padding, etc), there's a |
| /// `finish()` method on this type that encodes any leftover input bytes and adds padding if |
| /// appropriate. It's called automatically when deallocated (see the `Drop` implementation), but |
| /// any error that occurs when invoking the underlying writer will be suppressed. If you want to |
| /// handle such errors, call `finish()` yourself. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::io::Write; |
| /// use base64::engine::general_purpose; |
| /// |
| /// // use a vec as the simplest possible `Write` -- in real code this is probably a file, etc. |
| /// let mut enc = base64::write::EncoderWriter::new(Vec::new(), &general_purpose::STANDARD); |
| /// |
| /// // handle errors as you normally would |
| /// enc.write_all(b"asdf").unwrap(); |
| /// |
| /// // could leave this out to be called by Drop, if you don't care |
| /// // about handling errors or getting the delegate writer back |
| /// let delegate = enc.finish().unwrap(); |
| /// |
| /// // base64 was written to the writer |
| /// assert_eq!(b"YXNkZg==", &delegate[..]); |
| /// |
| /// ``` |
| /// |
| /// # Panics |
| /// |
| /// Calling `write()` (or related methods) or `finish()` after `finish()` has completed without |
| /// error is invalid and will panic. |
| /// |
| /// # Errors |
| /// |
| /// Base64 encoding itself does not generate errors, but errors from the wrapped writer will be |
| /// returned as per the contract of `Write`. |
| /// |
| /// # Performance |
| /// |
| /// It has some minor performance loss compared to encoding slices (a couple percent). |
| /// It does not do any heap allocation. |
| /// |
| /// # Limitations |
| /// |
| /// Owing to the specification of the `write` and `flush` methods on the `Write` trait and their |
| /// implications for a buffering implementation, these methods may not behave as expected. In |
| /// particular, calling `write_all` on this interface may fail with `io::ErrorKind::WriteZero`. |
| /// See the documentation of the `Write` trait implementation for further details. |
| </span><span class="kw">pub struct </span>EncoderWriter<<span class="lifetime">'e</span>, E: Engine, W: io::Write> { |
| engine: <span class="kw-2">&</span><span class="lifetime">'e </span>E, |
| <span class="doccomment">/// Where encoded data is written to. It's an Option as it's None immediately before Drop is |
| /// called so that finish() can return the underlying writer. None implies that finish() has |
| /// been called successfully. |
| </span>delegate: <span class="prelude-ty">Option</span><W>, |
| <span class="doccomment">/// Holds a partial chunk, if any, after the last `write()`, so that we may then fill the chunk |
| /// with the next `write()`, encode it, then proceed with the rest of the input normally. |
| </span>extra_input: [u8; MIN_ENCODE_CHUNK_SIZE], |
| <span class="doccomment">/// How much of `extra` is occupied, in `[0, MIN_ENCODE_CHUNK_SIZE]`. |
| </span>extra_input_occupied_len: usize, |
| <span class="doccomment">/// Buffer to encode into. May hold leftover encoded bytes from a previous write call that the underlying writer |
| /// did not write last time. |
| </span>output: [u8; BUF_SIZE], |
| <span class="doccomment">/// How much of `output` is occupied with encoded data that couldn't be written last time |
| </span>output_occupied_len: usize, |
| <span class="doccomment">/// panic safety: don't write again in destructor if writer panicked while we were writing to it |
| </span>panicked: bool, |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'e</span>, E: Engine, W: io::Write> fmt::Debug <span class="kw">for </span>EncoderWriter<<span class="lifetime">'e</span>, E, W> { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { |
| <span class="macro">write!</span>( |
| f, |
| <span class="string">"extra_input: {:?} extra_input_occupied_len:{:?} output[..5]: {:?} output_occupied_len: {:?}"</span>, |
| <span class="self">self</span>.extra_input, |
| <span class="self">self</span>.extra_input_occupied_len, |
| <span class="kw-2">&</span><span class="self">self</span>.output[<span class="number">0</span>..<span class="number">5</span>], |
| <span class="self">self</span>.output_occupied_len |
| ) |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'e</span>, E: Engine, W: io::Write> EncoderWriter<<span class="lifetime">'e</span>, E, W> { |
| <span class="doccomment">/// Create a new encoder that will write to the provided delegate writer. |
| </span><span class="kw">pub fn </span>new(delegate: W, engine: <span class="kw-2">&</span><span class="lifetime">'e </span>E) -> EncoderWriter<<span class="lifetime">'e</span>, E, W> { |
| EncoderWriter { |
| engine, |
| delegate: <span class="prelude-val">Some</span>(delegate), |
| extra_input: [<span class="number">0u8</span>; MIN_ENCODE_CHUNK_SIZE], |
| extra_input_occupied_len: <span class="number">0</span>, |
| output: [<span class="number">0u8</span>; BUF_SIZE], |
| output_occupied_len: <span class="number">0</span>, |
| panicked: <span class="bool-val">false</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Encode all remaining buffered data and write it, including any trailing incomplete input |
| /// triples and associated padding. |
| /// |
| /// Once this succeeds, no further writes or calls to this method are allowed. |
| /// |
| /// This may write to the delegate writer multiple times if the delegate writer does not accept |
| /// all input provided to its `write` each invocation. |
| /// |
| /// If you don't care about error handling, it is not necessary to call this function, as the |
| /// equivalent finalization is done by the Drop impl. |
| /// |
| /// Returns the writer that this was constructed around. |
| /// |
| /// # Errors |
| /// |
| /// The first error that is not of `ErrorKind::Interrupted` will be returned. |
| </span><span class="kw">pub fn </span>finish(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><W> { |
| <span class="comment">// If we could consume self in finish(), we wouldn't have to worry about this case, but |
| // finish() is retryable in the face of I/O errors, so we can't consume here. |
| </span><span class="kw">if </span><span class="self">self</span>.delegate.is_none() { |
| <span class="macro">panic!</span>(<span class="string">"Encoder has already had finish() called"</span>); |
| }; |
| |
| <span class="self">self</span>.write_final_leftovers()<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span>writer = <span class="self">self</span>.delegate.take().expect(<span class="string">"Writer must be present"</span>); |
| |
| <span class="prelude-val">Ok</span>(writer) |
| } |
| |
| <span class="doccomment">/// Write any remaining buffered data to the delegate writer. |
| </span><span class="kw">fn </span>write_final_leftovers(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">if </span><span class="self">self</span>.delegate.is_none() { |
| <span class="comment">// finish() has already successfully called this, and we are now in drop() with a None |
| // writer, so just no-op |
| </span><span class="kw">return </span><span class="prelude-val">Ok</span>(()); |
| } |
| |
| <span class="self">self</span>.write_all_encoded_output()<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><span class="self">self</span>.extra_input_occupied_len > <span class="number">0 </span>{ |
| <span class="kw">let </span>encoded_len = <span class="self">self |
| </span>.engine |
| .encode_slice( |
| <span class="kw-2">&</span><span class="self">self</span>.extra_input[..<span class="self">self</span>.extra_input_occupied_len], |
| <span class="kw-2">&mut </span><span class="self">self</span>.output[..], |
| ) |
| .expect(<span class="string">"buffer is large enough"</span>); |
| |
| <span class="self">self</span>.output_occupied_len = encoded_len; |
| |
| <span class="self">self</span>.write_all_encoded_output()<span class="question-mark">?</span>; |
| |
| <span class="comment">// write succeeded, do not write the encoding of extra again if finish() is retried |
| </span><span class="self">self</span>.extra_input_occupied_len = <span class="number">0</span>; |
| } |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Write as much of the encoded output to the delegate writer as it will accept, and store the |
| /// leftovers to be attempted at the next write() call. Updates `self.output_occupied_len`. |
| /// |
| /// # Errors |
| /// |
| /// Errors from the delegate writer are returned. In the case of an error, |
| /// `self.output_occupied_len` will not be updated, as errors from `write` are specified to mean |
| /// that no write took place. |
| </span><span class="kw">fn </span>write_to_delegate(<span class="kw-2">&mut </span><span class="self">self</span>, current_output_len: usize) -> <span class="prelude-ty">Result</span><()> { |
| <span class="self">self</span>.panicked = <span class="bool-val">true</span>; |
| <span class="kw">let </span>res = <span class="self">self |
| </span>.delegate |
| .as_mut() |
| .expect(<span class="string">"Writer must be present"</span>) |
| .write(<span class="kw-2">&</span><span class="self">self</span>.output[..current_output_len]); |
| <span class="self">self</span>.panicked = <span class="bool-val">false</span>; |
| |
| res.map(|consumed| { |
| <span class="macro">debug_assert!</span>(consumed <= current_output_len); |
| |
| <span class="kw">if </span>consumed < current_output_len { |
| <span class="self">self</span>.output_occupied_len = current_output_len.checked_sub(consumed).unwrap(); |
| <span class="comment">// If we're blocking on I/O, the minor inefficiency of copying bytes to the |
| // start of the buffer is the least of our concerns... |
| // TODO Rotate moves more than we need to; copy_within now stable. |
| </span><span class="self">self</span>.output.rotate_left(consumed); |
| } <span class="kw">else </span>{ |
| <span class="self">self</span>.output_occupied_len = <span class="number">0</span>; |
| } |
| }) |
| } |
| |
| <span class="doccomment">/// Write all buffered encoded output. If this returns `Ok`, `self.output_occupied_len` is `0`. |
| /// |
| /// This is basically write_all for the remaining buffered data but without the undesirable |
| /// abort-on-`Ok(0)` behavior. |
| /// |
| /// # Errors |
| /// |
| /// Any error emitted by the delegate writer abort the write loop and is returned, unless it's |
| /// `Interrupted`, in which case the error is ignored and writes will continue. |
| </span><span class="kw">fn </span>write_all_encoded_output(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><()> { |
| <span class="kw">while </span><span class="self">self</span>.output_occupied_len > <span class="number">0 </span>{ |
| <span class="kw">let </span>remaining_len = <span class="self">self</span>.output_occupied_len; |
| <span class="kw">match </span><span class="self">self</span>.write_to_delegate(remaining_len) { |
| <span class="comment">// try again on interrupts ala write_all |
| </span><span class="prelude-val">Err</span>(<span class="kw-2">ref </span>e) <span class="kw">if </span>e.kind() == ErrorKind::Interrupted => {} |
| <span class="comment">// other errors return |
| </span><span class="prelude-val">Err</span>(e) => <span class="kw">return </span><span class="prelude-val">Err</span>(e), |
| <span class="comment">// success no-ops because remaining length is already updated |
| </span><span class="prelude-val">Ok</span>(<span class="kw">_</span>) => {} |
| }; |
| } |
| |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, <span class="self">self</span>.output_occupied_len); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="doccomment">/// Unwraps this `EncoderWriter`, returning the base writer it writes base64 encoded output |
| /// to. |
| /// |
| /// Normally this method should not be needed, since `finish()` returns the inner writer if |
| /// it completes successfully. That will also ensure all data has been flushed, which the |
| /// `into_inner()` function does *not* do. |
| /// |
| /// Calling this method after `finish()` has completed successfully will panic, since the |
| /// writer has already been returned. |
| /// |
| /// This method may be useful if the writer implements additional APIs beyond the `Write` |
| /// trait. Note that the inner writer might be in an error state or have an incomplete |
| /// base64 string written to it. |
| </span><span class="kw">pub fn </span>into_inner(<span class="kw-2">mut </span><span class="self">self</span>) -> W { |
| <span class="self">self</span>.delegate |
| .take() |
| .expect(<span class="string">"Encoder has already had finish() called"</span>) |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'e</span>, E: Engine, W: io::Write> io::Write <span class="kw">for </span>EncoderWriter<<span class="lifetime">'e</span>, E, W> { |
| <span class="doccomment">/// Encode input and then write to the delegate writer. |
| /// |
| /// Under non-error circumstances, this returns `Ok` with the value being the number of bytes |
| /// of `input` consumed. The value may be `0`, which interacts poorly with `write_all`, which |
| /// interprets `Ok(0)` as an error, despite it being allowed by the contract of `write`. See |
| /// <https://github.com/rust-lang/rust/issues/56889> for more on that. |
| /// |
| /// If the previous call to `write` provided more (encoded) data than the delegate writer could |
| /// accept in a single call to its `write`, the remaining data is buffered. As long as buffered |
| /// data is present, subsequent calls to `write` will try to write the remaining buffered data |
| /// to the delegate and return either `Ok(0)` -- and therefore not consume any of `input` -- or |
| /// an error. |
| /// |
| /// # Errors |
| /// |
| /// Any errors emitted by the delegate writer are returned. |
| </span><span class="kw">fn </span>write(<span class="kw-2">&mut </span><span class="self">self</span>, input: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Result</span><usize> { |
| <span class="kw">if </span><span class="self">self</span>.delegate.is_none() { |
| <span class="macro">panic!</span>(<span class="string">"Cannot write more after calling finish()"</span>); |
| } |
| |
| <span class="kw">if </span>input.is_empty() { |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="number">0</span>); |
| } |
| |
| <span class="comment">// The contract of `Write::write` places some constraints on this implementation: |
| // - a call to `write()` represents at most one call to a wrapped `Write`, so we can't |
| // iterate over the input and encode multiple chunks. |
| // - Errors mean that "no bytes were written to this writer", so we need to reset the |
| // internal state to what it was before the error occurred |
| |
| // before reading any input, write any leftover encoded output from last time |
| </span><span class="kw">if </span><span class="self">self</span>.output_occupied_len > <span class="number">0 </span>{ |
| <span class="kw">let </span>current_len = <span class="self">self</span>.output_occupied_len; |
| <span class="kw">return </span><span class="self">self |
| </span>.write_to_delegate(current_len) |
| <span class="comment">// did not read any input |
| </span>.map(|<span class="kw">_</span>| <span class="number">0</span>); |
| } |
| |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, <span class="self">self</span>.output_occupied_len); |
| |
| <span class="comment">// how many bytes, if any, were read into `extra` to create a triple to encode |
| </span><span class="kw">let </span><span class="kw-2">mut </span>extra_input_read_len = <span class="number">0</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>input = input; |
| |
| <span class="kw">let </span>orig_extra_len = <span class="self">self</span>.extra_input_occupied_len; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>encoded_size = <span class="number">0</span>; |
| <span class="comment">// always a multiple of MIN_ENCODE_CHUNK_SIZE |
| </span><span class="kw">let </span><span class="kw-2">mut </span>max_input_len = MAX_INPUT_LEN; |
| |
| <span class="comment">// process leftover un-encoded input from last write |
| </span><span class="kw">if </span><span class="self">self</span>.extra_input_occupied_len > <span class="number">0 </span>{ |
| <span class="macro">debug_assert!</span>(<span class="self">self</span>.extra_input_occupied_len < <span class="number">3</span>); |
| <span class="kw">if </span>input.len() + <span class="self">self</span>.extra_input_occupied_len >= MIN_ENCODE_CHUNK_SIZE { |
| <span class="comment">// Fill up `extra`, encode that into `output`, and consume as much of the rest of |
| // `input` as possible. |
| // We could write just the encoding of `extra` by itself but then we'd have to |
| // return after writing only 4 bytes, which is inefficient if the underlying writer |
| // would make a syscall. |
| </span>extra_input_read_len = MIN_ENCODE_CHUNK_SIZE - <span class="self">self</span>.extra_input_occupied_len; |
| <span class="macro">debug_assert!</span>(extra_input_read_len > <span class="number">0</span>); |
| <span class="comment">// overwrite only bytes that weren't already used. If we need to rollback extra_len |
| // (when the subsequent write errors), the old leading bytes will still be there. |
| </span><span class="self">self</span>.extra_input[<span class="self">self</span>.extra_input_occupied_len..MIN_ENCODE_CHUNK_SIZE] |
| .copy_from_slice(<span class="kw-2">&</span>input[<span class="number">0</span>..extra_input_read_len]); |
| |
| <span class="kw">let </span>len = <span class="self">self</span>.engine.internal_encode( |
| <span class="kw-2">&</span><span class="self">self</span>.extra_input[<span class="number">0</span>..MIN_ENCODE_CHUNK_SIZE], |
| <span class="kw-2">&mut </span><span class="self">self</span>.output[..], |
| ); |
| <span class="macro">debug_assert_eq!</span>(<span class="number">4</span>, len); |
| |
| input = <span class="kw-2">&</span>input[extra_input_read_len..]; |
| |
| <span class="comment">// consider extra to be used up, since we encoded it |
| </span><span class="self">self</span>.extra_input_occupied_len = <span class="number">0</span>; |
| <span class="comment">// don't clobber where we just encoded to |
| </span>encoded_size = <span class="number">4</span>; |
| <span class="comment">// and don't read more than can be encoded |
| </span>max_input_len = MAX_INPUT_LEN - MIN_ENCODE_CHUNK_SIZE; |
| |
| <span class="comment">// fall through to normal encoding |
| </span>} <span class="kw">else </span>{ |
| <span class="comment">// `extra` and `input` are non empty, but `|extra| + |input| < 3`, so there must be |
| // 1 byte in each. |
| </span><span class="macro">debug_assert_eq!</span>(<span class="number">1</span>, input.len()); |
| <span class="macro">debug_assert_eq!</span>(<span class="number">1</span>, <span class="self">self</span>.extra_input_occupied_len); |
| |
| <span class="self">self</span>.extra_input[<span class="self">self</span>.extra_input_occupied_len] = input[<span class="number">0</span>]; |
| <span class="self">self</span>.extra_input_occupied_len += <span class="number">1</span>; |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="number">1</span>); |
| }; |
| } <span class="kw">else if </span>input.len() < MIN_ENCODE_CHUNK_SIZE { |
| <span class="comment">// `extra` is empty, and `input` fits inside it |
| </span><span class="self">self</span>.extra_input[<span class="number">0</span>..input.len()].copy_from_slice(input); |
| <span class="self">self</span>.extra_input_occupied_len = input.len(); |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(input.len()); |
| }; |
| |
| <span class="comment">// either 0 or 1 complete chunks encoded from extra |
| </span><span class="macro">debug_assert!</span>(encoded_size == <span class="number">0 </span>|| encoded_size == <span class="number">4</span>); |
| <span class="macro">debug_assert!</span>( |
| <span class="comment">// didn't encode extra input |
| </span>MAX_INPUT_LEN == max_input_len |
| <span class="comment">// encoded one triple |
| </span>|| MAX_INPUT_LEN == max_input_len + MIN_ENCODE_CHUNK_SIZE |
| ); |
| |
| <span class="comment">// encode complete triples only |
| </span><span class="kw">let </span>input_complete_chunks_len = input.len() - (input.len() % MIN_ENCODE_CHUNK_SIZE); |
| <span class="kw">let </span>input_chunks_to_encode_len = cmp::min(input_complete_chunks_len, max_input_len); |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, max_input_len % MIN_ENCODE_CHUNK_SIZE); |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, input_chunks_to_encode_len % MIN_ENCODE_CHUNK_SIZE); |
| |
| encoded_size += <span class="self">self</span>.engine.internal_encode( |
| <span class="kw-2">&</span>input[..(input_chunks_to_encode_len)], |
| <span class="kw-2">&mut </span><span class="self">self</span>.output[encoded_size..], |
| ); |
| |
| <span class="comment">// not updating `self.output_occupied_len` here because if the below write fails, it should |
| // "never take place" -- the buffer contents we encoded are ignored and perhaps retried |
| // later, if the consumer chooses. |
| |
| </span><span class="self">self</span>.write_to_delegate(encoded_size) |
| <span class="comment">// no matter whether we wrote the full encoded buffer or not, we consumed the same |
| // input |
| </span>.map(|<span class="kw">_</span>| extra_input_read_len + input_chunks_to_encode_len) |
| .map_err(|e| { |
| <span class="comment">// in case we filled and encoded `extra`, reset extra_len |
| </span><span class="self">self</span>.extra_input_occupied_len = orig_extra_len; |
| |
| e |
| }) |
| } |
| |
| <span class="doccomment">/// Because this is usually treated as OK to call multiple times, it will *not* flush any |
| /// incomplete chunks of input or write padding. |
| /// # Errors |
| /// |
| /// The first error that is not of [`ErrorKind::Interrupted`] will be returned. |
| </span><span class="kw">fn </span>flush(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><()> { |
| <span class="self">self</span>.write_all_encoded_output()<span class="question-mark">?</span>; |
| <span class="self">self</span>.delegate |
| .as_mut() |
| .expect(<span class="string">"Writer must be present"</span>) |
| .flush() |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'e</span>, E: Engine, W: io::Write> Drop <span class="kw">for </span>EncoderWriter<<span class="lifetime">'e</span>, E, W> { |
| <span class="kw">fn </span>drop(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="kw">if </span>!<span class="self">self</span>.panicked { |
| <span class="comment">// like `BufWriter`, ignore errors during drop |
| </span><span class="kw">let _ </span>= <span class="self">self</span>.write_final_leftovers(); |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="base64" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
