/*@jsxRuntime automatic @jsxImportSource react*/ const {Fragment: _Fragment, jsx: _jsx, jsxs: _jsxs} = arguments[0]; function MDXContent(props = {}) { const {wrapper: MDXLayout} = props.components || ({}); return MDXLayout ? _jsx(MDXLayout, Object.assign({}, props, { children: _jsx(_createMdxContent, {}) })) : _createMdxContent(); function _createMdxContent() { const _components = Object.assign({ blockquote: "blockquote", p: "p", pre: "pre", code: "code", span: "span" }, props.components); return _jsxs(_Fragment, { children: [_jsxs(_components.blockquote, { children: ["\n", _jsx(_components.p, { children: "This article is based on a vagrant Ubuntu system with an SSD so you might encounter different results." }), "\n"] }), "\n", _jsx(_components.p, { children: "When reading and writing files in C++ it is important to use the correct buffer size or the block size. This will drastically improve the time it takes to read in files or write to files." }), "\n", _jsx(_components.p, { children: "Let's create a 10Mb file in C++ with the following code (we are not using a buffer here since we are benchmarking the reading so this doesn't matter):" }), "\n", _jsx(_components.pre, { className: "language-c", children: _jsxs(_components.code, { className: "language-c code-highlight", children: [_jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token string", children: "" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token string", children: "" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// rand, srand" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// time" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// perror" })] }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [_jsx(_components.span, { className: "token keyword", children: "int" }), " ", _jsx(_components.span, { className: "token function", children: "main" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "int" }), " argc", _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token keyword", children: "char" }), _jsx(_components.span, { className: "token operator", children: "*" }), _jsx(_components.span, { className: "token operator", children: "*" }), " argv", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "srand" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token function", children: "time" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Open file in write only, create if not exist and always truncate mode." }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "int" }), " fd", _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "open" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token string", children: "\"test.txt\"" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " O_WRONLY ", _jsx(_components.span, { className: "token operator", children: "|" }), " O_CREAT ", _jsx(_components.span, { className: "token operator", children: "|" }), " O_TRUNC", _jsx(_components.span, { className: "token punctuation", children: "," }), " S_IRUSR ", _jsx(_components.span, { className: "token operator", children: "|" }), " S_IRGRP ", _jsx(_components.span, { className: "token operator", children: "|" }), " S_IROTH", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "return" }), " ", _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Write 10Mb chars" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "for" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "int" }), " i ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), " i ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "10" }), " ", _jsx(_components.span, { className: "token operator", children: "*" }), " ", _jsx(_components.span, { className: "token number", children: "1024" }), " ", _jsx(_components.span, { className: "token operator", children: "*" }), " ", _jsx(_components.span, { className: "token number", children: "1024" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), " i", _jsx(_components.span, { className: "token operator", children: "++" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "int" }), " cr ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "rand" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "%" }), " ", _jsx(_components.span, { className: "token number", children: "26" }), " ", _jsx(_components.span, { className: "token operator", children: "+" }), " ", _jsx(_components.span, { className: "token char", children: "'a'" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Write 1 byte char to fd" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token function", children: "write" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd", _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token operator", children: "&" }), "cr", _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "!=" }), " ", _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Close the FD" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token function", children: "close" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "return" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] })] }) }), "\n", _jsx(_components.p, { children: "This simply create a text file with random characters from the alphabet in it for 10Mb." }), "\n", _jsx(_components.p, { children: "Now when we want to read this file we can do this in different block sizes. This next piece of code will time how long it takes to read in the file with different block sizes." }), "\n", _jsx(_components.pre, { className: "language-c", children: _jsxs(_components.code, { className: "language-c code-highlight", children: [_jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token string", children: "" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token string", children: "" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// read" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// rand, srand" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// time" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// perror" })] }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsxs(_components.span, { className: "token macro property", children: [_jsx(_components.span, { className: "token directive-hash", children: "#" }), _jsx(_components.span, { className: "token directive keyword", children: "include" }), " ", _jsx(_components.span, { className: "token comment", children: "// malloc" })] }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [_jsx(_components.span, { className: "token keyword", children: "int" }), " ", _jsx(_components.span, { className: "token function", children: "main" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "int" }), " argc", _jsx(_components.span, { className: "token punctuation", children: "," }), " ", _jsx(_components.span, { className: "token keyword", children: "char" }), _jsx(_components.span, { className: "token operator", children: "*" }), _jsx(_components.span, { className: "token operator", children: "*" }), " argv", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Read 10Mb in decrementing BUF_SIZES into the buffer" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "for" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "int" }), " i ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), " i ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "8192" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), " i ", _jsx(_components.span, { className: "token operator", children: "<<=" }), " ", _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Create buffer to load it in" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "char" }), " ", _jsx(_components.span, { className: "token operator", children: "*" }), "buffer ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "char" }), " ", _jsx(_components.span, { className: "token operator", children: "*" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token function", children: "malloc" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "sizeof" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token keyword", children: "char" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "*" }), " i", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Start timing" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "double" }), " start ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "clock" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Open file in write only, create if not exist and always truncate mode." }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "int" }), " fd", _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Open file" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "open" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token string", children: "\"test.txt\"" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " O_RDONLY", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "free" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "buffer", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token comment", children: "// Keep reading the count while count == i, this means we have still remaining bytes" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "int" }), " count", _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "count ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token function", children: "read" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd", _jsx(_components.span, { className: "token punctuation", children: "," }), " buffer", _jsx(_components.span, { className: "token punctuation", children: "," }), " i", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "free" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "buffer", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "while" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), "count ", _jsx(_components.span, { className: "token operator", children: "==" }), " i", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "count ", _jsx(_components.span, { className: "token operator", children: "==" }), " ", _jsx(_components.span, { className: "token function", children: "read" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd", _jsx(_components.span, { className: "token punctuation", children: "," }), " buffer", _jsx(_components.span, { className: "token punctuation", children: "," }), " i", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "free" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "buffer", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "double" }), " end ", _jsx(_components.span, { className: "token operator", children: "=" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token function", children: "clock" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "-" }), " start", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "/" }), " CLOCKS_PER_SEC", _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "printf" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token string", children: "\"BUF_SIZE=%6d Time=%4fn\"" }), _jsx(_components.span, { className: "token punctuation", children: "," }), " i", _jsx(_components.span, { className: "token punctuation", children: "," }), " end", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "free" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "buffer", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "if" }), " ", _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token function", children: "close" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "fd", _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token operator", children: "<" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), " ", _jsx(_components.span, { className: "token punctuation", children: "{" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "free" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "buffer", _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "perror" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), "argv", _jsx(_components.span, { className: "token punctuation", children: "[" }), _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: "]" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token function", children: "exit" }), _jsx(_components.span, { className: "token punctuation", children: "(" }), _jsx(_components.span, { className: "token number", children: "1" }), _jsx(_components.span, { className: "token punctuation", children: ")" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] }), _jsx(_components.span, { className: "code-line", children: "\n" }), _jsxs(_components.span, { className: "code-line", children: [" ", _jsx(_components.span, { className: "token keyword", children: "return" }), " ", _jsx(_components.span, { className: "token number", children: "0" }), _jsx(_components.span, { className: "token punctuation", children: ";" }), "\n"] }), _jsxs(_components.span, { className: "code-line", children: [_jsx(_components.span, { className: "token punctuation", children: "}" }), "\n"] })] }) }), "\n", _jsx(_components.p, { children: "After running this file we get the following result:" }), "\n", _jsx(_components.pre, { children: _jsxs(_components.code, { className: "code-highlight", children: [_jsx(_components.span, { className: "code-line", children: "$ make main && ./main\n" }), _jsx(_components.span, { className: "code-line", children: "g++ main.cpp -o main\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 1 Time=0.39\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 2 Time=0.27\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 4 Time=0.19\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 8 Time=0.08\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 16 Time=0.03\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 32 Time=0.02\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 64 Time=0.02\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 128 Time=0.01\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 256 Time=0.00\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 512 Time=0.00\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=1024 Time=0.00\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=2048 Time=0.00\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=4096 Time=0.00\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=8192 Time=0.00\n" })] }) }), "\n", _jsx(_components.p, { children: "We can clearly see that when using a buffer size of 1 that the performance is slower then when using a buffer size of 256 or 8. Now let's create a 100Mb file and execute it on that new file." }), "\n", _jsx(_components.pre, { children: _jsxs(_components.code, { className: "code-highlight", children: [_jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 1 Time=3.66\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 2 Time=1.91\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 4 Time=0.95\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 8 Time=0.40\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 16 Time=0.20\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 32 Time=0.11\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 64 Time=0.07\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 128 Time=0.04\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 256 Time=0.01\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ= 512 Time=0.02\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=1024 Time=0.01\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=2048 Time=0.01\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=4096 Time=0.01\n" }), _jsx(_components.span, { className: "code-line", children: "BUF_SIZ=8192 Time=0.01\n" })] }) }), "\n", _jsx(_components.p, { children: "We can now clearly see that the bigger the buffer size the faster the reading, however when the buffer size gets big enough the performance gain is almost the same." })] }); } } return { default: MDXContent };

Are you struggling with testing and integrating AI into your product?

Are you struggling with testing and integrating AI into your product?