2 /******************************************************************************
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3 * Copyright (C) 2008 by Diego Arroyuelo *
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4 * Interface for the in-memory XQuery/XPath engine *
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6 * This program is free software; you can redistribute it and/or modify *
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7 * it under the terms of the GNU Lesser General Public License as published *
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8 * by the Free Software Foundation; either version 2 of the License, or *
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9 * (at your option) any later version. *
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11 * This program is distributed in the hope that it will be useful, *
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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14 * GNU Lesser General Public License for more details. *
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16 * You should have received a copy of the GNU Lesser General Public License *
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17 * along with this program; if not, write to the *
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18 * Free Software Foundation, Inc., *
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19 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
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20 ******************************************************************************/
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24 #include "TextCollection/TextCollection.h"
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30 //clash between TextCollection/Tools.h and libcds/includes/basics.h
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36 #include <static_bitsequence.h>
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37 #include <alphabet_mapper.h>
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38 #include <static_sequence.h>
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39 using SXSI::TextCollection;
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42 // this constant is used to efficiently compute the child operation in the tree
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47 #define PERM_SAMPLE 10
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50 #define bitset(e,p) ((e)[(p)/W] |= (1<<((p)%W)))
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51 // cleans bit p in e
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52 #define bitclean(e,p) ((e)[(p)/W] &= ~(1<<((p)%W)))
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55 typedef int treeNode;
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56 typedef int TagType;
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66 // I know this class implements the working draft that we have but the logics seem flawed here...
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67 // We should have two classes. One XMLTreeBuilder and one XMLTree.
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68 // XMLTreeBuilder would have OpenDocument, NewOpenTag,... and CloseDocument would return an XMLTree
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69 // XMLTree would have only an initialized structure. If find it really ugly to check (!finished) or (!initialized)
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70 // in every function (FirstChild....).
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73 /** Balanced parentheses representation of the tree */
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76 /** Mapping from tag identifer to tag name */
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77 unsigned char **TagName;
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79 /** boolean flag indicating whether we are indexing empty texts or not */
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80 bool indexing_empty_texts;
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82 /** Bit vector indicating with a 1 the positions of the non-empty texts. */
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83 static_bitsequence_rrr02 *EBVector;
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85 /** Tag sequence represented with a data structure for rank and select */
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86 static_sequence *Tags;
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88 uint tags_blen, tags_len;
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90 /** The texts in the XML document */
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91 TextCollection *Text;
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92 /** The texts in the XML document (cached for faster display) */
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93 vector<string> CachedText;
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95 /** Flag indicating whether the whole data structure has been constructed or
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96 * not. If the value is true, you cannot add more texts, nodes, etc. */
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99 /** Flag indicating whether the construction of the data structure has been
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100 * initialized or not (by calling method OpenDocument()). If this is true,
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101 * you cannot insert new tags or texts. */
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104 /* the following components are used for construction purposes */
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110 unsigned int *empty_texts_aux;
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113 // I added those two. The TagName array should always contains two special tags
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114 // <@> for attributes and <$> for PCDATA.
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115 // <$> can never be in a document (since we handle the text differently)
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116 // but <@> can be returned by the parser. This boolean is needed for the construction
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117 // of the Tag bitmap to know if <@> must be taken into account or not
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118 bool found_attributes;
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121 // Allows to disable the TextCollection for benchmarkin purposes
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126 /** Data structure constructor */
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127 XMLTree() {finished = false; initialized = false;};
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129 /** Data structure destructor */
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132 /** root(): returns the tree root. */
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135 /** SubtreeSize(x): the number of nodes (and attributes) in the subtree of
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137 int SubtreeSize(treeNode x);
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139 /** SubtreeTags(x,tag): the number of occurrences of tag within the subtree
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141 int SubtreeTags(treeNode x, TagType tag);
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143 /** IsLeaf(x): returns whether node x is leaf or not. In the succinct
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144 * representation this is just a bit inspection. */
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145 bool IsLeaf(treeNode x);
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147 /** IsAncestor(x,y): returns whether node x is ancestor of node y. */
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148 bool IsAncestor(treeNode x, treeNode y);
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150 /** IsChild(x,y): returns whether node x is parent of node y. */
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151 bool IsChild(treeNode x, treeNode y);
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153 /** NumChildren(x): number of children of node x. Constant time with the
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154 * data structure of Sadakane. */
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155 int NumChildren(treeNode x);
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157 /** ChildNumber(x): returns i if node x is the i-th children of its
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159 inline int ChildNumber(treeNode x);
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161 /** Depth(x): depth of node x, a simple binary rank on the parentheses
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163 int Depth(treeNode x);
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165 /** Preorder(x): returns the preorder number of node x, just regarding tree
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166 * nodes (and not texts). */
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167 int Preorder(treeNode x);
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169 /** Postorder(x): returns the postorder number of node x, just regarding
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170 * tree nodes (and not texts). */
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171 int Postorder(treeNode x);
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173 /** Tag(x): returns the tag identifier of node x. */
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174 TagType Tag(treeNode x);
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176 /** DocIds(x): returns the range (i.e., a pair of integers) of document
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177 * identifiers that descend from node x. */
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178 range DocIds(treeNode x);
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180 /** Parent(x): returns the parent node of node x. */
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181 treeNode Parent(treeNode x);
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183 /** Child(x,i): returns the i-th child of node x, assuming it exists. */
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184 treeNode Child(treeNode x, int i);
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186 /** FirstChild(x): returns the first child of node x, assuming it exists.
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187 * Very fast in BP. */
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188 treeNode FirstChild(treeNode x);
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190 /** NextSibling(x): returns the next sibling of node x, assuming it
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192 treeNode NextSibling(treeNode x);
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194 /** PrevSibling(x): returns the previous sibling of node x, assuming it
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196 treeNode PrevSibling(treeNode x);
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198 /** TaggedChild(x,i,tag): returns the i-th child of node x tagged tag, or
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199 * NULLT if there is none. Because of the balanced-parentheses representation
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200 * of the tree, this operation is not supported efficiently, just iterating
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201 * among the children of node x until finding the desired child. */
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202 treeNode TaggedChild(treeNode x, int i, TagType tag);
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204 /** TaggedDesc(x,tag): returns the first node tagged tag with larger
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205 * preorder than x and within the subtree of x. Returns NULT if there
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207 treeNode TaggedDesc(treeNode x, TagType tag);
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209 /** TaggedNext(x,tag): returns the first node tagged tag with larger
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210 * preorder than x. Returns NULT if there is none. */
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211 treeNode TaggedNext(treeNode x, TagType tag);
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213 /** TaggedPrec(x,tag): returns the first node tagged tag with smaller
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214 * preorder than x and not an ancestor of x. Returns NULLT if there
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216 treeNode TaggedPrec(treeNode x, TagType tag);
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218 /** TaggedFoll(x,tag): returns the first node tagged tag with larger
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219 * preorder than x and not in the subtree of x. Returns NULLT if there
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221 treeNode TaggedFoll(treeNode x, TagType tag);
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223 /** TaggedFollowingSibling(x,tag) */
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224 treeNode TaggedFollowingSibling(treeNode x, TagType tag);
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226 /** TaggedAncestor(x, tag): returns the closest ancestor of x tagged
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227 * tag. Return NULLT is there is none. */
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228 treeNode TaggedAncestor(treeNode x, TagType tag);
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230 /** PrevText(x): returns the document identifier of the text to the left of
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231 * node x, or NULLT if x is the root node. */
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232 DocID PrevText(treeNode x);
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234 /** NextText(x): returns the document identifier of the text to the right of
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235 * node x, or NULLT if x is the root node. */
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236 DocID NextText(treeNode x);
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238 /** MyText(x): returns the document identifier of the text below node x, or
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239 * NULLT if x is not a leaf node. */
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240 DocID MyText(treeNode x);
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242 /** TextXMLId(d): returns the preorder of document with identifier d in the
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243 * tree consisting of all tree nodes and all text nodes. */
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244 int TextXMLId(DocID d);
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246 /** NodeXMLId(x): returns the preorder of node x in the tree consisting of
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247 * all tree nodes and all text nodes. */
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248 int NodeXMLId(treeNode x);
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250 /** ParentNode(d): returns the parent node of document identifier d. */
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251 treeNode ParentNode(DocID d);
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253 /** OpenDocument(empty_texts,sample_rate_text,dtc): initilizes the construction
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254 * of the data structure for the XML document. Parameter empty_texts
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255 * indicates whether we index empty texts in document or not. Parameter
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256 * sample_rate_text indicates the sampling rate for the text searching data
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257 * structures (small values get faster searching but a bigger space
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258 * requirement). dtc disable the use of the TextCollection
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259 * (i.e. everything is considered an empty text *)
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260 * Returns a non-zero value upon success, NULLT in case of
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263 int OpenDocument(bool empty_texts, int sample_rate_text, bool dtc);
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265 /** CloseDocument(): finishes the construction of the data structure for
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266 * the XML document. Tree and tags are represented in the final form,
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267 * dynamic data structures are made static, and the flag "finished" is set
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268 * to true. After that, the data structure can be queried. */
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269 int CloseDocument();
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271 /** NewOpenTag(tagname): indicates the event of finding a new opening tag
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272 * in the document. Tag name is given. Returns a non-zero value upon
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273 * success, and returns NULLT in case of error. */
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274 int NewOpenTag(unsigned char *tagname);
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276 /** NewClosingTag(tagname): indicates the event of finding a new closing tag
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277 * in the document. Tag name is given. Returns a non-zero value upon
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278 * success, and returns NULLT in case of error. */
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279 int NewClosingTag(unsigned char *tagname);
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281 /** NewText(s): indicates the event of finding a new (non-empty) text s in
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282 * the document. The new text is inserted within the text collection.
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283 * Returns a non-zero value upon success, NULLT in case of error. */
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284 int NewText(unsigned char *s);
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286 /** NewEmptyText(): indicates the event of finding a new empty text in the
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287 * document. In case of indexing empty and non-empty texts, we insert the
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288 * empty texts into the text collection. In case of indexing only non-empty
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289 * texts, it just indicates an empty text in the bit vector of empty texts.
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290 * Returns a non-zero value upon success, NULLT in case of error. */
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291 int NewEmptyText();
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293 /** GetTagId(tagname): returns the tag identifier corresponding to a given
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294 * tag name. Returns NULLT in case that the tag name does not exists. */
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295 TagType GetTagId(unsigned char *tagname);
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297 /** GetTagName(tagid): returns the tag name of a given tag identifier.
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298 * Returns NULL in case that the tag identifier is not valid.*/
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299 unsigned char *GetTagName(TagType tagid);
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303 /** GetTagName(tagid): returns the tag name of a given tag identifier.
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304 * The result is just a reference and should not be freed by the caller.
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306 const unsigned char *GetTagNameByRef(TagType tagid);
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309 /** RegisterTag adds a new tag to the tag collection this is needed
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310 * if the query contains a tag which is not in the document, we need
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311 * to give this new tag a fresh id and store it somewhere. A logical
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313 * We might want to use a hashtable instead of an array though.
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315 TagType RegisterTag(unsigned char *tagname);
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317 bool EmptyText(DocID i) {
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318 return Text->EmptyText(i);
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320 /** Prefix(s): search for texts prefixed by string s. */
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321 TextCollection::document_result Prefix(uchar const *s) {
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322 return Text->Prefix(s);
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325 /** Suffix(s): search for texts having string s as a suffix. */
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326 TextCollection::document_result Suffix(uchar const *s) {
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327 return Text->Suffix(s);
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330 /** Equal(s): search for texts equal to string s. */
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331 TextCollection::document_result Equal(uchar const *s) {
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332 return Text->Equal(s);
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335 /** Contains(s): search for texts containing string s. */
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336 TextCollection::document_result Contains(uchar const *s) {
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337 return Text->Contains(s);
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340 /** LessThan(s): returns document identifiers for the texts that
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341 * are lexicographically smaller than string s. */
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342 TextCollection::document_result LessThan(uchar const *s) {
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343 return Text->LessThan(s);
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346 /** IsPrefix(x): returns true if there is a text prefixed by string s. */
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347 bool IsPrefix(uchar const *s) {
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348 return Text->IsPrefix(s);
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351 /** IsSuffix(s): returns true if there is a text having string s as a
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353 bool IsSuffix(uchar const *s) {
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354 return Text->IsSuffix(s);
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357 /** IsEqual(s): returns true if there is a text that equals given
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359 bool IsEqual(uchar const *s) {
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360 return Text->IsEqual(s);
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363 /** IsContains(s): returns true if there is a text containing string s. */
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364 bool IsContains(uchar const *s) {
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365 return Text->IsContains(s);
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368 /** IsLessThan(s): returns true if there is at least a text that is
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369 * lexicographically smaller than string s. */
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370 bool IsLessThan(uchar const *s) {
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371 return Text->IsLessThan(s);
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374 /** CountPrefix(s): counting version of Prefix(s). */
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375 unsigned CountPrefix(uchar const *s) {
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376 return Text->CountPrefix(s);
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379 /** CountSuffix(s): counting version of Suffix(s). */
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380 unsigned CountSuffix(uchar const *s) {
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381 return Text->CountSuffix(s);
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384 /** CountEqual(s): counting version of Equal(s). */
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385 unsigned CountEqual(uchar const *s) {
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386 return Text->CountEqual(s);
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389 /** CountContains(s): counting version of Contains(s). */
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390 unsigned CountContains(uchar const *s) {
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391 return Text->CountContains(s);
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394 /** CountLessThan(s): counting version of LessThan(s). */
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395 unsigned CountLessThan(uchar const *s) {
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396 return CountLessThan(s);
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399 /** GetText(d): returns the text corresponding to document with
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401 uchar* GetText(DocID d) {
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402 return Text->GetText(d);
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405 uchar* GetCachedText(DocID d) {
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406 uchar * str = (uchar*) calloc(sizeof(char),(CachedText.at(d).size() + 1));
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407 strcpy((char*) str,(const char*) CachedText.at(d).c_str());
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408 return (uchar*) (str);
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411 TextCollection *getTextCollection() {
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414 /** Save: saves XML tree data structure to file. */
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415 void Save(unsigned char *filename);
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417 /** Load: loads XML tree data structure from file. sample_rate_text
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418 * indicates the sample rate for the text search data structure. */
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419 static XMLTree *Load(unsigned char *filename, int sample_rate_text);
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