src/server/etag.cpp
77.8% Lines (21/27)
75.0% Functions (3/4)
| Line | TLA | Hits | Source Code |
|---|---|---|---|
| 1 | // | ||
| 2 | // Copyright (c) 2025 Vinnie Falco ([email protected]) | ||
| 3 | // | ||
| 4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | ||
| 5 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
| 6 | // | ||
| 7 | // Official repository: https://github.com/cppalliance/http | ||
| 8 | // | ||
| 9 | |||
| 10 | #include <boost/http/server/etag.hpp> | ||
| 11 | #include <cstdio> | ||
| 12 | |||
| 13 | namespace boost { | ||
| 14 | namespace http { | ||
| 15 | |||
| 16 | namespace { | ||
| 17 | |||
| 18 | // Simple FNV-1a hash for content | ||
| 19 | std::uint64_t | ||
| 20 | 1 | fnv1a_hash( core::string_view data ) noexcept | |
| 21 | { | ||
| 22 | 1 | constexpr std::uint64_t basis = 14695981039346656037ULL; | |
| 23 | 1 | constexpr std::uint64_t prime = 1099511628211ULL; | |
| 24 | |||
| 25 | 1 | std::uint64_t hash = basis; | |
| 26 | 3 | for( unsigned char c : data ) | |
| 27 | { | ||
| 28 | 2 | hash ^= c; | |
| 29 | 2 | hash *= prime; | |
| 30 | } | ||
| 31 | 1 | return hash; | |
| 32 | } | ||
| 33 | |||
| 34 | // Convert to null-terminated hex string | ||
| 35 | void | ||
| 36 | 1 | to_hex( std::uint64_t value, char* out ) noexcept | |
| 37 | { | ||
| 38 | 1 | constexpr char hex[] = "0123456789abcdef"; | |
| 39 | 17 | for( int i = 15; i >= 0; --i ) | |
| 40 | { | ||
| 41 | 16 | out[i] = hex[value & 0xF]; | |
| 42 | 16 | value >>= 4; | |
| 43 | } | ||
| 44 | 1 | out[16] = '\0'; | |
| 45 | 1 | } | |
| 46 | |||
| 47 | } // (anon) | ||
| 48 | |||
| 49 | std::string | ||
| 50 | 1 | etag( core::string_view body, etag_options opts ) | |
| 51 | { | ||
| 52 | 1 | auto const hash = fnv1a_hash( body ); | |
| 53 | |||
| 54 | char hex[17]; | ||
| 55 | 1 | to_hex( hash, hex ); | |
| 56 | |||
| 57 | char buf[64]; | ||
| 58 | int n; | ||
| 59 | 1 | if( opts.weak ) | |
| 60 | ✗ | n = std::snprintf( buf, sizeof(buf), | |
| 61 | "W/\"%zx-%s\"", body.size(), hex ); | ||
| 62 | else | ||
| 63 | 1 | n = std::snprintf( buf, sizeof(buf), | |
| 64 | "\"%zx-%s\"", body.size(), hex ); | ||
| 65 | |||
| 66 | 2 | return std::string( buf, static_cast<std::size_t>(n) ); | |
| 67 | } | ||
| 68 | |||
| 69 | std::string | ||
| 70 | ✗ | etag( | |
| 71 | std::uint64_t size, | ||
| 72 | std::uint64_t mtime, | ||
| 73 | etag_options opts ) | ||
| 74 | { | ||
| 75 | char buf[64]; | ||
| 76 | int n; | ||
| 77 | ✗ | if( opts.weak ) | |
| 78 | ✗ | n = std::snprintf( buf, sizeof(buf), | |
| 79 | "W/\"%llx-%llx\"", | ||
| 80 | static_cast<unsigned long long>( size ), | ||
| 81 | static_cast<unsigned long long>( mtime ) ); | ||
| 82 | else | ||
| 83 | ✗ | n = std::snprintf( buf, sizeof(buf), | |
| 84 | "\"%llx-%llx\"", | ||
| 85 | static_cast<unsigned long long>( size ), | ||
| 86 | static_cast<unsigned long long>( mtime ) ); | ||
| 87 | |||
| 88 | ✗ | return std::string( buf, static_cast<std::size_t>(n) ); | |
| 89 | } | ||
| 90 | |||
| 91 | } // http | ||
| 92 | } // boost | ||
| 93 |