|
| 1 | +# libdivsufsort |
| 2 | + |
| 3 | +libdivsufsort is a software library that implements a lightweight suffix array construction algorithm. |
| 4 | + |
| 5 | +## News |
| 6 | +* 2015-03-21: The project has moved from [Google Code](http://code.google.com/p/libdivsufsort/) to [GitHub](https://github.com/y-256/libdivsufsort) |
| 7 | + |
| 8 | +## Introduction |
| 9 | +This library provides a simple and an efficient C API to construct a suffix array and a Burrows-Wheeler transformed string from a given string over a constant-size alphabet. |
| 10 | +The algorithm runs in O(n log n) worst-case time using only 5n+O(1) bytes of memory space, where n is the length of |
| 11 | +the string. |
| 12 | + |
| 13 | +## Build requirements |
| 14 | +* An ANSI C Compiler (e.g. GNU GCC) |
| 15 | +* [CMake](http://www.cmake.org/ "CMake") version 2.4.2 or newer |
| 16 | +* CMake-supported build tool |
| 17 | + |
| 18 | +## Building on GNU/Linux |
| 19 | +1. Get the source code from GitHub. You can either |
| 20 | + * use git to clone the repository |
| 21 | + ``` |
| 22 | + git clone https://github.com/y-256/libdivsufsort.git |
| 23 | + ``` |
| 24 | + * or download a [zip file](../../archive/master.zip) directly |
| 25 | +2. Create a `build` directory in the package source directory. |
| 26 | +```shell |
| 27 | +$ cd libdivsufsort |
| 28 | +$ mkdir build |
| 29 | +$ cd build |
| 30 | +``` |
| 31 | +3. Configure the package for your system. |
| 32 | +If you want to install to a different location, change the -DCMAKE_INSTALL_PREFIX option. |
| 33 | +```shell |
| 34 | +$ cmake -DCMAKE_BUILD_TYPE="Release" \ |
| 35 | +-DCMAKE_INSTALL_PREFIX="/usr/local" .. |
| 36 | +``` |
| 37 | +4. Compile the package. |
| 38 | +```shell |
| 39 | +$ make |
| 40 | +``` |
| 41 | +5. (Optional) Install the library and header files. |
| 42 | +```shell |
| 43 | +$ sudo make install |
| 44 | +``` |
| 45 | + |
| 46 | +## API |
| 47 | +```c |
| 48 | +/* Data types */ |
| 49 | +typedef int32_t saint_t; |
| 50 | +typedef int32_t saidx_t; |
| 51 | +typedef uint8_t sauchar_t; |
| 52 | + |
| 53 | +/* |
| 54 | + * Constructs the suffix array of a given string. |
| 55 | + * @param T[0..n-1] The input string. |
| 56 | + * @param SA[0..n-1] The output array or suffixes. |
| 57 | + * @param n The length of the given string. |
| 58 | + * @return 0 if no error occurred, -1 or -2 otherwise. |
| 59 | + */ |
| 60 | +saint_t |
| 61 | +divsufsort(const sauchar_t *T, saidx_t *SA, saidx_t n); |
| 62 | + |
| 63 | +/* |
| 64 | + * Constructs the burrows-wheeler transformed string of a given string. |
| 65 | + * @param T[0..n-1] The input string. |
| 66 | + * @param U[0..n-1] The output string. (can be T) |
| 67 | + * @param A[0..n-1] The temporary array. (can be NULL) |
| 68 | + * @param n The length of the given string. |
| 69 | + * @return The primary index if no error occurred, -1 or -2 otherwise. |
| 70 | + */ |
| 71 | +saidx_t |
| 72 | +divbwt(const sauchar_t *T, sauchar_t *U, saidx_t *A, saidx_t n); |
| 73 | +``` |
| 74 | +
|
| 75 | +## Example Usage |
| 76 | +```c |
| 77 | +#include <stdio.h> |
| 78 | +#include <stdlib.h> |
| 79 | +#include <string.h> |
| 80 | +
|
| 81 | +#include <divsufsort.h> |
| 82 | +
|
| 83 | +int main() { |
| 84 | + // intput data |
| 85 | + char *Text = "abracadabra"; |
| 86 | + int n = strlen(Text); |
| 87 | + int i, j; |
| 88 | +
|
| 89 | + // allocate |
| 90 | + int *SA = (int *)malloc(n * sizeof(int)); |
| 91 | +
|
| 92 | + // sort |
| 93 | + divsufsort((unsigned char *)Text, SA, n); |
| 94 | +
|
| 95 | + // output |
| 96 | + for(i = 0; i < n; ++i) { |
| 97 | + printf("SA[%2d] = %2d: ", i, SA[i]); |
| 98 | + for(j = SA[i]; j < n; ++j) { |
| 99 | + printf("%c", Text[j]); |
| 100 | + } |
| 101 | + printf("$\n"); |
| 102 | + } |
| 103 | +
|
| 104 | + // deallocate |
| 105 | + free(SA); |
| 106 | +
|
| 107 | + return 0; |
| 108 | +} |
| 109 | +``` |
| 110 | +See the [examples](examples) directory for a few other examples. |
| 111 | + |
| 112 | +## Benchmarks |
| 113 | +See [Benchmarks](https://github.com/y-256/libdivsufsort/blob/wiki/SACA_Benchmarks.md) page for details. |
| 114 | + |
| 115 | +## License |
| 116 | +libdivsufsort is released under the [MIT license](LICENSE "MIT license"). |
| 117 | +> The MIT License (MIT) |
| 118 | +> |
| 119 | +> Copyright (c) 2003 Yuta Mori All rights reserved. |
| 120 | +> |
| 121 | +> Permission is hereby granted, free of charge, to any person obtaining a copy |
| 122 | +> of this software and associated documentation files (the "Software"), to deal |
| 123 | +> in the Software without restriction, including without limitation the rights |
| 124 | +> to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 125 | +> copies of the Software, and to permit persons to whom the Software is |
| 126 | +> furnished to do so, subject to the following conditions: |
| 127 | +> |
| 128 | +> The above copyright notice and this permission notice shall be included in all |
| 129 | +> copies or substantial portions of the Software. |
| 130 | +> |
| 131 | +> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 132 | +> IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 133 | +> FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 134 | +> AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 135 | +> LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 136 | +> OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 137 | +> SOFTWARE. |
| 138 | +
|
| 139 | +## Author |
| 140 | +* Yuta Mori |
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