1 | /**************************************** |
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2 | * Computer Algebra System SINGULAR * |
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3 | ****************************************/ |
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4 | /*************************************************************** |
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5 | * File: sbuckets.cc |
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6 | * Purpose: implementation of routines for sorting polys using |
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7 | * a bucket sort |
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8 | * Author: obachman (Olaf Bachmann) |
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9 | * Created: 9/00 |
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10 | * Version: $Id$ |
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11 | *******************************************************************/ |
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12 | //#include <kernel/mod2.h> |
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13 | |
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14 | #include <polys/sbuckets.h> |
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15 | #include <omalloc/omalloc.h> |
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16 | #include <polys/monomials/ring.h> |
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17 | //#include <kernel/p_Procs.h> |
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18 | #include <polys/monomials//p_polys.h> |
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19 | |
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20 | |
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21 | |
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22 | ////////////////////////////////////////////////////////////////////////// |
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23 | // Declarations |
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24 | // |
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25 | |
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26 | class sBucketPoly |
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27 | { |
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28 | public: |
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29 | poly p; |
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30 | long length; |
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31 | }; |
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32 | |
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33 | class sBucket |
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34 | { |
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35 | public: |
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36 | ring bucket_ring; |
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37 | long max_bucket; |
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38 | sBucketPoly buckets[BIT_SIZEOF_LONG - 3]; |
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39 | } |
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40 | ; |
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41 | |
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42 | static omBin sBucket_bin = omGetSpecBin(sizeof(sBucket)); |
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43 | |
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44 | |
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45 | ////////////////////////////////////////////////////////////////////////// |
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46 | // New API: |
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47 | // |
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48 | |
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49 | /// Returns bucket ring |
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50 | ring sBucketGetRing(const sBucket_pt bucket) |
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51 | { return bucket->bucket_ring; } |
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52 | |
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53 | /// Copy sBucket non-intrusive!!! |
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54 | sBucket_pt sBucketCopy(const sBucket_pt bucket) |
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55 | { |
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56 | const ring r = bucket->bucket_ring; |
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57 | |
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58 | sBucket_pt newbucket = sBucketCreate(r); |
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59 | |
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60 | for(int i = 0; bucket->buckets[i].p != NULL; i++) |
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61 | { |
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62 | assume( i < (BIT_SIZEOF_LONG - 3) ); |
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63 | assume( pLength(bucket->buckets[i].p) == bucket->buckets[i].length ); |
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64 | |
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65 | newbucket->buckets[i].p = p_Copy(bucket->buckets[i].p, r); |
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66 | newbucket->buckets[i].length = bucket->buckets[i].length; |
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67 | |
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68 | assume( pLength(newbucket->buckets[i].p) == newbucket->buckets[i].length ); |
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69 | } |
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70 | |
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71 | return newbucket; |
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72 | } |
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73 | |
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74 | ///////////////////////////////////////////////////////////////////////////// |
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75 | // internal routines |
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76 | // |
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77 | // returns floor(log_2(i)) |
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78 | static inline int LOG2(int i) |
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79 | { |
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80 | assume (i > 0); |
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81 | int j = 0; |
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82 | |
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83 | do |
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84 | { |
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85 | i = i >> 1; |
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86 | if (i == 0) return j; |
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87 | j++; |
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88 | } |
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89 | while (1); |
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90 | |
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91 | return j; |
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92 | } |
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93 | |
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94 | ////////////////////////////////////////////////////////////////////////// |
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95 | // Creation/Destruction of buckets |
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96 | // |
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97 | sBucket_pt sBucketCreate(ring r) |
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98 | { |
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99 | sBucket_pt bucket = (sBucket_pt) omAlloc0Bin(sBucket_bin); |
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100 | bucket->bucket_ring = r; |
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101 | return bucket; |
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102 | } |
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103 | |
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104 | void sBucketDestroy(sBucket_pt *bucket) |
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105 | { |
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106 | assume(bucket != NULL); |
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107 | omFreeBin(*bucket, sBucket_bin); |
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108 | *bucket = NULL; |
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109 | } |
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110 | |
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111 | void sBucketDeleteAndDestroy(sBucket_pt *bucket_pt) |
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112 | { |
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113 | sBucket_pt bucket = *bucket_pt; |
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114 | int i; |
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115 | for (i=0; i<= bucket->max_bucket; i++) |
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116 | { |
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117 | |
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118 | if (bucket->buckets[i].p != NULL) |
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119 | { |
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120 | p_Delete(&(bucket->buckets[i].p), bucket->bucket_ring); |
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121 | } |
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122 | } |
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123 | omFreeBin(bucket, sBucket_bin); |
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124 | *bucket_pt = NULL; |
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125 | } |
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126 | |
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127 | |
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128 | ///////////////////////////////////////////////////////////////////////////// |
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129 | // Convertion from/to SBpolys |
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130 | // |
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131 | |
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132 | static void sBucket_Merge_m(sBucket_pt bucket, poly p) |
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133 | { |
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134 | assume(p != NULL && pNext(p) == NULL); |
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135 | int length = 1; |
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136 | int i = 0; |
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137 | |
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138 | while (bucket->buckets[i].p != NULL) |
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139 | { |
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140 | p = p_Merge_q(p, bucket->buckets[i].p, bucket->bucket_ring); |
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141 | length += bucket->buckets[i].length; |
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142 | bucket->buckets[i].p = NULL; |
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143 | bucket->buckets[i].length = 0; |
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144 | i++; |
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145 | assume(LOG2(length) == i); |
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146 | } |
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147 | |
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148 | bucket->buckets[i].p = p; |
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149 | bucket->buckets[i].length = length; |
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150 | if (i > bucket->max_bucket) bucket->max_bucket = i; |
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151 | } |
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152 | |
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153 | void sBucket_Merge_p(sBucket_pt bucket, poly p, int length) |
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154 | { |
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155 | assume(bucket != NULL); |
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156 | assume(length <= 0 || length == pLength(p)); |
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157 | |
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158 | if (p == NULL) return; |
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159 | if (length <= 0) length = pLength(p); |
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160 | |
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161 | int i = LOG2(length); |
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162 | |
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163 | while (bucket->buckets[i].p != NULL) |
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164 | { |
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165 | p = p_Merge_q(p, bucket->buckets[i].p, bucket->bucket_ring); |
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166 | length += bucket->buckets[i].length; |
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167 | bucket->buckets[i].p = NULL; |
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168 | bucket->buckets[i].length = 0; |
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169 | i++; |
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170 | assume(LOG2(length) == i); |
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171 | } |
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172 | |
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173 | bucket->buckets[i].p = p; |
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174 | bucket->buckets[i].length = length; |
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175 | if (i > bucket->max_bucket) bucket->max_bucket = i; |
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176 | } |
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177 | |
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178 | void sBucket_Add_p(sBucket_pt bucket, poly p, int length) |
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179 | { |
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180 | assume(bucket != NULL); |
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181 | assume(length <= 0 || length == pLength(p)); |
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182 | |
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183 | if (p == NULL) return; |
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184 | if (length <= 0) length = pLength(p); |
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185 | |
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186 | int i = LOG2(length); |
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187 | |
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188 | while (bucket->buckets[i].p != NULL) |
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189 | { |
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190 | p = p_Add_q(p, bucket->buckets[i].p, length, bucket->buckets[i].length, |
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191 | bucket->bucket_ring); |
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192 | bucket->buckets[i].p = NULL; |
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193 | bucket->buckets[i].length = 0; |
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194 | if (p==NULL) |
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195 | { |
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196 | if (i > bucket->max_bucket) bucket->max_bucket = i; |
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197 | return; |
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198 | } |
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199 | i = LOG2(length); |
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200 | } |
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201 | |
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202 | bucket->buckets[i].p = p; |
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203 | bucket->buckets[i].length = length; |
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204 | if (i > bucket->max_bucket) bucket->max_bucket = i; |
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205 | } |
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206 | |
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207 | // Converts SBpoly into a poly and clears bucket |
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208 | // i.e., afterwards SBpoly == 0 |
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209 | void sBucketClearMerge(sBucket_pt bucket, poly *p, int *length) |
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210 | { |
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211 | poly pr = NULL; |
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212 | int lr = 0; |
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213 | int i = 0; |
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214 | |
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215 | while (bucket->buckets[i].p == NULL) |
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216 | { |
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217 | i++; |
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218 | if (i > bucket->max_bucket) goto done; |
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219 | } |
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220 | |
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221 | pr = bucket->buckets[i].p; |
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222 | lr = bucket->buckets[i].length; |
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223 | bucket->buckets[i].p = NULL; |
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224 | bucket->buckets[i].length = 0; |
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225 | i++; |
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226 | |
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227 | while (i <= bucket->max_bucket) |
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228 | { |
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229 | if (bucket->buckets[i].p != NULL) |
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230 | { |
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231 | pr = p_Merge_q(pr, bucket->buckets[i].p,bucket->bucket_ring); |
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232 | lr += bucket->buckets[i].length; |
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233 | bucket->buckets[i].p = NULL; |
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234 | bucket->buckets[i].length = 0; |
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235 | } |
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236 | i++; |
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237 | } |
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238 | |
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239 | done: |
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240 | *p = pr; |
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241 | *length = lr; |
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242 | bucket->max_bucket = 0; |
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243 | } |
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244 | |
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245 | // Converts SBpoly into a poly and clears bucket |
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246 | // i.e., afterwards SBpoly == 0 |
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247 | void sBucketClearAdd(sBucket_pt bucket, poly *p, int *length) |
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248 | { |
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249 | poly pr = NULL; |
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250 | int lr = 0; |
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251 | int i = 0; |
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252 | |
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253 | while (bucket->buckets[i].p == NULL) |
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254 | { |
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255 | i++; |
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256 | if (i > bucket->max_bucket) goto done; |
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257 | } |
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258 | |
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259 | pr = bucket->buckets[i].p; |
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260 | lr = bucket->buckets[i].length; |
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261 | bucket->buckets[i].p = NULL; |
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262 | bucket->buckets[i].length = 0; |
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263 | i++; |
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264 | |
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265 | while (i <= bucket->max_bucket) |
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266 | { |
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267 | if (bucket->buckets[i].p != NULL) |
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268 | { |
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269 | pr = p_Add_q(pr, bucket->buckets[i].p, lr, bucket->buckets[i].length, |
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270 | bucket->bucket_ring); |
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271 | bucket->buckets[i].p = NULL; |
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272 | bucket->buckets[i].length = 0; |
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273 | } |
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274 | i++; |
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275 | } |
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276 | |
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277 | done: |
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278 | *p = pr; |
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279 | *length = lr; |
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280 | bucket->max_bucket = 0; |
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281 | } |
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282 | |
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283 | ///////////////////////////////////////////////////////////////////////////// |
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284 | // Sorts a poly using BucketSort |
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285 | // |
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286 | |
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287 | poly sBucketSortMerge(poly p, ring r) |
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288 | { |
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289 | #ifdef HAVE_ASSUME |
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290 | int l_in = pLength(p); |
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291 | #endif |
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292 | |
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293 | if (p == NULL || pNext(p) == NULL) return p; |
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294 | |
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295 | sBucket_pt bucket = sBucketCreate(r); |
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296 | poly pn = pNext(p); |
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297 | |
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298 | do |
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299 | { |
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300 | pNext(p) = NULL; |
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301 | sBucket_Merge_m(bucket, p); |
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302 | p = pn; |
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303 | if (p == NULL) break; |
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304 | pn = pNext(pn); |
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305 | } |
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306 | while (1); |
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307 | |
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308 | int l_dummy; |
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309 | sBucketClearMerge(bucket, &pn, &l_dummy); |
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310 | sBucketDestroy(&bucket); |
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311 | |
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312 | p_Test(pn, r); |
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313 | #ifdef HAVE_ASSUME |
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314 | assume(l_dummy == pLength(pn)); |
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315 | assume(l_in == l_dummy); |
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316 | #endif |
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317 | return pn; |
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318 | } |
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319 | |
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320 | ///////////////////////////////////////////////////////////////////////////// |
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321 | // Sorts a poly using BucketSort |
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322 | // |
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323 | |
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324 | poly sBucketSortAdd(poly p, ring r) |
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325 | { |
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326 | #ifdef HAVE_ASSUME |
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327 | int l_in = pLength(p); |
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328 | #endif |
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329 | |
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330 | if (p == NULL || pNext(p) == NULL) return p; |
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331 | |
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332 | sBucket_pt bucket = sBucketCreate(r); |
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333 | poly pn = pNext(p); |
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334 | |
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335 | do |
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336 | { |
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337 | pNext(p) = NULL; |
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338 | sBucket_Add_p(bucket, p, 1); |
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339 | p = pn; |
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340 | if (p == NULL) break; |
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341 | pn = pNext(pn); |
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342 | } |
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343 | while (1); |
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344 | |
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345 | int l_dummy; |
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346 | sBucketClearAdd(bucket, &pn, &l_dummy); |
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347 | sBucketDestroy(&bucket); |
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348 | |
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349 | p_Test(pn, r); |
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350 | #ifdef HAVE_ASSUME |
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351 | assume(l_dummy == pLength(pn)); |
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352 | assume(l_in >= l_dummy); |
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353 | #endif |
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354 | return pn; |
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355 | } |
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