| <!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 `common/rusty_leveldb_sgx/src/write_batch.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>write_batch.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="../../rusty_leveldb/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="../../rusty_leveldb/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>::key_types::ValueType; |
| <span class="kw">use </span><span class="kw">crate</span>::memtable::MemTable; |
| <span class="kw">use </span><span class="kw">crate</span>::types::SequenceNumber; |
| <span class="kw">use </span>integer_encoding::{FixedInt, VarInt, VarIntWriter}; |
| |
| <span class="kw">use </span>std::io::Write; |
| |
| <span class="kw">const </span>SEQNUM_OFFSET: usize = <span class="number">0</span>; |
| <span class="kw">const </span>COUNT_OFFSET: usize = <span class="number">8</span>; |
| <span class="kw">const </span>HEADER_SIZE: usize = <span class="number">12</span>; |
| |
| <span class="doccomment">/// A WriteBatch contains entries to be written to a MemTable (for example) in a compact form. |
| /// |
| /// The storage format is (with the respective length in bytes) |
| /// |
| /// [tag: 1, keylen: ~var, key: keylen, vallen: ~var, val: vallen] |
| </span><span class="kw">pub struct </span>WriteBatch { |
| entries: Vec<u8>, |
| } |
| |
| <span class="kw">impl </span>WriteBatch { |
| <span class="kw">pub fn </span>new() -> WriteBatch { |
| <span class="kw">let </span><span class="kw-2">mut </span>v = Vec::with_capacity(<span class="number">128</span>); |
| v.resize(HEADER_SIZE, <span class="number">0</span>); |
| |
| WriteBatch { entries: v } |
| } |
| |
| <span class="doccomment">/// Initializes a WriteBatch with a serialized WriteBatch. |
| </span><span class="kw">pub fn </span>set_contents(<span class="kw-2">&mut </span><span class="self">self</span>, from: <span class="kw-2">&</span>[u8]) { |
| <span class="self">self</span>.entries.clear(); |
| <span class="self">self</span>.entries.extend_from_slice(from); |
| } |
| |
| <span class="doccomment">/// Adds an entry to a WriteBatch, to be added to the database. |
| </span><span class="attribute">#[allow(unused_assignments)] |
| </span><span class="kw">pub fn </span>put(<span class="kw-2">&mut </span><span class="self">self</span>, k: <span class="kw-2">&</span>[u8], v: <span class="kw-2">&</span>[u8]) { |
| <span class="self">self</span>.entries |
| .write_all(<span class="kw-2">&</span>[ValueType::TypeValue <span class="kw">as </span>u8]) |
| .unwrap(); |
| <span class="self">self</span>.entries.write_varint(k.len()).unwrap(); |
| <span class="self">self</span>.entries.write_all(k).unwrap(); |
| <span class="self">self</span>.entries.write_varint(v.len()).unwrap(); |
| <span class="self">self</span>.entries.write_all(v).unwrap(); |
| |
| <span class="kw">let </span>c = <span class="self">self</span>.count(); |
| <span class="self">self</span>.set_count(c + <span class="number">1</span>); |
| } |
| |
| <span class="doccomment">/// Marks an entry to be deleted from the database. |
| </span><span class="attribute">#[allow(unused_assignments)] |
| </span><span class="kw">pub fn </span>delete(<span class="kw-2">&mut </span><span class="self">self</span>, k: <span class="kw-2">&</span>[u8]) { |
| <span class="self">self</span>.entries |
| .write_all(<span class="kw-2">&</span>[ValueType::TypeDeletion <span class="kw">as </span>u8]) |
| .unwrap(); |
| <span class="self">self</span>.entries.write_varint(k.len()).unwrap(); |
| <span class="self">self</span>.entries.write(k).unwrap(); |
| |
| <span class="kw">let </span>c = <span class="self">self</span>.count(); |
| <span class="self">self</span>.set_count(c + <span class="number">1</span>); |
| } |
| |
| <span class="doccomment">/// Clear the contents of a WriteBatch. |
| </span><span class="kw">pub fn </span>clear(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="self">self</span>.entries.clear() |
| } |
| |
| <span class="kw">fn </span>byte_size(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="self">self</span>.entries.len() |
| } |
| |
| <span class="kw">fn </span>set_count(<span class="kw-2">&mut </span><span class="self">self</span>, c: u32) { |
| c.encode_fixed(<span class="kw-2">&mut </span><span class="self">self</span>.entries[COUNT_OFFSET..COUNT_OFFSET + <span class="number">4</span>]); |
| } |
| |
| <span class="doccomment">/// Returns how many operations are in a batch. |
| </span><span class="kw">pub fn </span>count(<span class="kw-2">&</span><span class="self">self</span>) -> u32 { |
| u32::decode_fixed(<span class="kw-2">&</span><span class="self">self</span>.entries[COUNT_OFFSET..COUNT_OFFSET + <span class="number">4</span>]) |
| } |
| |
| <span class="kw">fn </span>set_sequence(<span class="kw-2">&mut </span><span class="self">self</span>, s: SequenceNumber) { |
| s.encode_fixed(<span class="kw-2">&mut </span><span class="self">self</span>.entries[SEQNUM_OFFSET..SEQNUM_OFFSET + <span class="number">8</span>]); |
| } |
| |
| <span class="kw">pub fn </span>sequence(<span class="kw-2">&</span><span class="self">self</span>) -> SequenceNumber { |
| u64::decode_fixed(<span class="kw-2">&</span><span class="self">self</span>.entries[SEQNUM_OFFSET..SEQNUM_OFFSET + <span class="number">8</span>]) |
| } |
| |
| <span class="kw">pub fn </span>iter(<span class="kw-2">&</span><span class="self">self</span>) -> WriteBatchIter { |
| WriteBatchIter { |
| batch: <span class="self">self</span>, |
| ix: HEADER_SIZE, |
| } |
| } |
| |
| <span class="kw">pub fn </span>insert_into_memtable(<span class="kw-2">&</span><span class="self">self</span>, <span class="kw-2">mut </span>seq: SequenceNumber, mt: <span class="kw-2">&mut </span>MemTable) { |
| <span class="kw">for </span>(k, v) <span class="kw">in </span><span class="self">self</span>.iter() { |
| <span class="kw">match </span>v { |
| <span class="prelude-val">Some</span>(v_) => mt.add(seq, ValueType::TypeValue, k, v_), |
| <span class="prelude-val">None </span>=> mt.add(seq, ValueType::TypeDeletion, k, <span class="string">""</span>.as_bytes()), |
| } |
| seq += <span class="number">1</span>; |
| } |
| } |
| |
| <span class="kw">pub fn </span>encode(<span class="kw-2">mut </span><span class="self">self</span>, seq: SequenceNumber) -> Vec<u8> { |
| <span class="self">self</span>.set_sequence(seq); |
| <span class="self">self</span>.entries |
| } |
| } |
| |
| <span class="kw">pub struct </span>WriteBatchIter<<span class="lifetime">'a</span>> { |
| batch: <span class="kw-2">&</span><span class="lifetime">'a </span>WriteBatch, |
| ix: usize, |
| } |
| |
| <span class="doccomment">/// The iterator also plays the role of the decoder. |
| </span><span class="kw">impl</span><<span class="lifetime">'a</span>> Iterator <span class="kw">for </span>WriteBatchIter<<span class="lifetime">'a</span>> { |
| <span class="kw">type </span>Item = (<span class="kw-2">&</span><span class="lifetime">'a </span>[u8], <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'a </span>[u8]>); |
| <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { |
| <span class="kw">if </span><span class="self">self</span>.ix >= <span class="self">self</span>.batch.entries.len() { |
| <span class="kw">return </span><span class="prelude-val">None</span>; |
| } |
| |
| <span class="kw">let </span>tag = <span class="self">self</span>.batch.entries[<span class="self">self</span>.ix]; |
| <span class="self">self</span>.ix += <span class="number">1</span>; |
| |
| <span class="kw">let </span>(klen, l) = usize::decode_var(<span class="kw-2">&</span><span class="self">self</span>.batch.entries[<span class="self">self</span>.ix..]); |
| <span class="self">self</span>.ix += l; |
| <span class="kw">let </span>k = <span class="kw-2">&</span><span class="self">self</span>.batch.entries[<span class="self">self</span>.ix..<span class="self">self</span>.ix + klen]; |
| <span class="self">self</span>.ix += klen; |
| |
| <span class="kw">if </span>tag == ValueType::TypeValue <span class="kw">as </span>u8 { |
| <span class="kw">let </span>(vlen, m) = usize::decode_var(<span class="kw-2">&</span><span class="self">self</span>.batch.entries[<span class="self">self</span>.ix..]); |
| <span class="self">self</span>.ix += m; |
| <span class="kw">let </span>v = <span class="kw-2">&</span><span class="self">self</span>.batch.entries[<span class="self">self</span>.ix..<span class="self">self</span>.ix + vlen]; |
| <span class="self">self</span>.ix += vlen; |
| |
| <span class="kw">return </span><span class="prelude-val">Some</span>((k, <span class="prelude-val">Some</span>(v))); |
| } <span class="kw">else </span>{ |
| <span class="kw">return </span><span class="prelude-val">Some</span>((k, <span class="prelude-val">None</span>)); |
| } |
| } |
| } |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"enclave_unit_test"</span>)] |
| </span><span class="kw">pub mod </span>tests { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| <span class="kw">use </span>std::iter::Iterator; |
| <span class="kw">use </span>teaclave_test_utils::<span class="kw-2">*</span>; |
| |
| <span class="kw">pub fn </span>run_tests() -> bool { |
| <span class="macro">run_tests!</span>(test_write_batch,) |
| } |
| |
| <span class="kw">fn </span>test_write_batch() { |
| <span class="kw">let </span><span class="kw-2">mut </span>b = WriteBatch::new(); |
| <span class="kw">let </span>entries = <span class="macro">vec!</span>[ |
| (<span class="string">"abc"</span>.as_bytes(), <span class="string">"def"</span>.as_bytes()), |
| (<span class="string">"123"</span>.as_bytes(), <span class="string">"456"</span>.as_bytes()), |
| (<span class="string">"xxx"</span>.as_bytes(), <span class="string">"yyy"</span>.as_bytes()), |
| (<span class="string">"zzz"</span>.as_bytes(), <span class="string">""</span>.as_bytes()), |
| (<span class="string">"010"</span>.as_bytes(), <span class="string">""</span>.as_bytes()), |
| ]; |
| |
| <span class="kw">for </span><span class="kw-2">&</span>(k, v) <span class="kw">in </span>entries.iter() { |
| <span class="kw">if </span>!v.is_empty() { |
| b.put(k, v); |
| } <span class="kw">else </span>{ |
| b.delete(k) |
| } |
| } |
| |
| <span class="macro">println!</span>(<span class="string">"{:?}"</span>, b.entries); |
| <span class="macro">assert_eq!</span>(b.byte_size(), <span class="number">49</span>); |
| <span class="macro">assert_eq!</span>(b.iter().count(), <span class="number">5</span>); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>i = <span class="number">0</span>; |
| |
| <span class="kw">for </span>(k, v) <span class="kw">in </span>b.iter() { |
| <span class="macro">assert_eq!</span>(k, entries[i].<span class="number">0</span>); |
| |
| <span class="kw">match </span>v { |
| <span class="prelude-val">None </span>=> <span class="macro">assert!</span>(entries[i].<span class="number">1</span>.is_empty()), |
| <span class="prelude-val">Some</span>(v_) => <span class="macro">assert_eq!</span>(v_, entries[i].<span class="number">1</span>), |
| } |
| |
| i += <span class="number">1</span>; |
| } |
| |
| <span class="macro">assert_eq!</span>(i, <span class="number">5</span>); |
| <span class="macro">assert_eq!</span>(b.encode(<span class="number">1</span>).len(), <span class="number">49</span>); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="rusty_leveldb" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
