如何将Ruby inlineC代码分离到多个文件？

Question

我想将MATCH宏和位图移动到一个单独的文件，因为我使用了这些地方，我想避免重复代码。这可能怎么做？

require 'inline' 

# Class to calculate the Levenshtein distance between two 
# given strings. 
# http://en.wikipedia.org/wiki/Levenshtein_distance 
class Levenshtein 
    BYTES_IN_INT = 4 

    def self.distance(s, t) 
    return 0  if s == t; 
    return t.length if s.length == 0; 
    return s.length if t.length == 0; 

    v0 = "\0" * (t.length + 1) * BYTES_IN_INT 
    v1 = "\0" * (t.length + 1) * BYTES_IN_INT 

    l = self.new 
    l.distance_C(s, t, s.length, t.length, v0, v1) 
    end 

    # >>>>>>>>>>>>>>> RubyInline C code <<<<<<<<<<<<<<< 

    inline do |builder| 
    # Macro for matching nucleotides including ambiguity codes. 
    builder.prefix %{ 
     #define MATCH(A,B) ((bitmap[A] & bitmap[B]) != 0) 
    } 

    # Bitmap for matching nucleotides including ambiguity codes. 
    # For each value bits are set from the left: bit pos 1 for A, 
    # bit pos 2 for T, bit pos 3 for C, and bit pos 4 for G. 
    builder.prefix %{ 
     char bitmap[256] = { 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0, 
      0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0, 
      0, 1,14, 4,11, 0, 0, 8, 7, 0, 0,10, 0, 5,15, 0, 
      0, 0, 9,12, 2, 2,13, 3, 0, 6, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 
     }; 
    } 

    builder.prefix %{ 
     unsigned int min(unsigned int a, unsigned int b, unsigned int c) 
     { 
      unsigned int m = a; 

      if (m > b) m = b; 
      if (m > c) m = c; 

      return m; 
     } 
    } 

    builder.c %{ 
     VALUE distance_C(
     VALUE _s,  // string 
     VALUE _t,  // string 
     VALUE _s_len, // string length 
     VALUE _t_len, // string length 
     VALUE _v0,  // score vector 
     VALUE _v1  // score vector 
    ) 
     { 
     char   *s  = (char *) StringValuePtr(_s); 
     char   *t  = (char *) StringValuePtr(_t); 
     unsigned int s_len = FIX2UINT(_s_len); 
     unsigned int t_len = FIX2UINT(_t_len); 
     unsigned int *v0 = (unsigned int *) StringValuePtr(_v0); 
     unsigned int *v1 = (unsigned int *) StringValuePtr(_v1); 

     unsigned int i = 0; 
     unsigned int j = 0; 
     unsigned int cost = 0; 

     for (i = 0; i < t_len + 1; i++) 
      v0[i] = i; 

     for (i = 0; i < s_len; i++) 
     { 
      v1[0] = i + 1; 

      for (j = 0; j < t_len; j++) 
      { 
      cost = (MATCH(s[i], t[j])) ? 0 : 1; 
      v1[j + 1] = min(v1[j] + 1, v0[j + 1] + 1, v0[j] + cost); 
      } 

      for (j = 0; j < t_len + 1; j++) 
      v0[j] = v1[j]; 
     } 

     return UINT2NUM(v1[t_len]); 
     } 
    } 
    end 
end 

Answer 1

builder.prefix只是一个方法调用，所以你可以创建一个Ruby方法与宏和字符数组称它，然后将其添加到要使用内嵌与C片段的任何类。例如

module MixinCommonC 
    def add_match_macro inline_builder 
    inline_builder.prefix %{ 
     #define MATCH(A,B) ((bitmap[A] & bitmap[B]) != 0) 
    } 
    end 
end 

在您的示例代码，您进行以下更改使用它：

在课程开始

class Levenshtein 
    extend MixinCommonC 

（这extend而不是include，因为inline方法是所以只能访问块内的类方法）

你现在拥有来电builder.prefix：

add_match_macro(builder)