X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=XMLTree.cpp;h=dfda61afa9467dd8049037bfef8866eec4ee82d1;hb=fadbf5f42541aa09769cbe406f5756fa042fe2d9;hp=cdfe95296d6e4310ac04356d18e374af0688600d;hpb=39ee9d4c866fd5e4ba478ef65dc7e714e80c0b91;p=SXSI%2FXMLTree.git

diff --git a/XMLTree.cpp b/XMLTree.cpp
index cdfe952..dfda61a 100644
--- a/XMLTree.cpp
+++ b/XMLTree.cpp
@@ -1,5 +1,64 @@
-#include "XMLTree.h"
+#include "basics.h"
 #include <cstring>
+#include <sstream>
+#include "XMLTree.h"
+#include <sys/time.h>
+#include <time.h>
+#include <sys/stat.h> 
+#include <unistd.h>
+
+static double tLoading = 0;
+
+static unsigned int cLoading = 0;
+static struct timeval tmpv1;
+static struct timeval tmpv2;
+static string mem1;
+static string mem2;
+
+void read_procmem(string& memstr) {
+  std::string buf;
+  pid_t pid = getpid();
+  std::stringstream path;
+  path <<  "/proc/" << pid << "/status";
+  std::ifstream infile;
+  infile.open (path.str().c_str(), std::ifstream::in);
+  while (infile.good()){
+    getline(infile,buf);
+    if (infile.eof()) {
+      memstr = "Could not read memory";
+      return;
+    };
+    int idx = buf.find("VmRSS");
+    if (idx == 0){
+      memstr = buf;
+      return;
+    };
+  };
+  memstr = "Could not read memory";
+  return;
+
+}
+
+#define STARTTIMER()   do {						\
+  gettimeofday(&tmpv1,NULL);						\
+  read_procmem(mem1);							\
+  } while (0)								\
+
+#define STOPTIMER(x)   do {						\
+    read_procmem(mem2);							\
+    gettimeofday(&tmpv2,NULL);						\
+    (t##x) = ((tmpv2.tv_sec  - tmpv1.tv_sec) * 1000000.0 +      	\
+		       (tmpv2.tv_usec  - tmpv1.tv_usec))/1000.0;	\
+    (c##x)= (c##x)+1;							\
+  } while (0)
+
+#define PRINTTIME(s,x) do {						\
+    std::cerr << (s) << " : " << (t##x) << "ms" << std::endl;		\
+    std::cerr << "Mem use before: " << mem1 << std::endl;		\
+    std::cerr << "Mem use after: " << mem2 << std::endl;		\
+    std::cerr.flush();							\
+  } while (0)								\
+
 
 // functions to convert tag positions to the corresponding tree node and viceversa. 
 // These are implemented in order to be able to change the tree and Tags representations, 
@@ -8,290 +67,251 @@
 // the tree, and storing 2 tags per tree node (opening and closing tags).
 
 // tag position -> tree node
-inline treeNode tagpos2node(int t) {
-   return (treeNode)t;
-}
+inline treeNode tagpos2node(int t) 
+ {
+    return (treeNode) t;
+ }
 
 // tree node -> tag position
-inline int node2tagpos(treeNode x) {
-   return (int)x;
+inline int node2tagpos(treeNode x) 
+{
+  return (int)x;
 }
 
+// returns NULLT if the test is true
+#define NULLT_IF(x)  do { if (x) return NULLT; } while (0)
 
-//KIM OJO to prevent suprious "unused result" warnings
 
-inline void ufread(void *ptr, size_t size, size_t nmemb, FILE *stream){
-  size_t res;
-  res = fread(ptr,size,nmemb,stream);
-  if (res < nmemb)
-    throw "ufread I/O error";
+XMLTree::XMLTree( pb * const par, uint npar,  vector<string> * const TN,  TagIdMap * const tim, uint *empty_texts_bmp, TagType *tags,
+            TextCollection * const TC, bool dis_tc)
 
-  return;
-}
+ {
+    // creates the data structure for the tree topology
+    Par = (bp *)umalloc(sizeof(bp));
+    bp_construct(Par, npar, (pb*) par, OPT_DEGREE|0);    
+   
+    // creates structure for tags
 
-inline void ufwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream){
-  size_t res;
-  res = fwrite(ptr,size,nmemb,stream);
-  if (res < nmemb)
-    throw "ufwrite I/O error";
-  return;
-}
+    TagName = (vector<string>*)TN;
+    tIdMap = (TagIdMap *) tim;
+    
+    uint max_tag = TN->size() - 1;
+      
+    static_bitsequence_builder *bmb = new static_bitsequence_builder_sdarray();
+    alphabet_mapper *am = new alphabet_mapper_none();
+    Tags = new static_sequence_bs((uint*)tags,npar,am,bmb);
+    
+    cout << "Tags test: " << Tags->test((uint*)tags,npar) << endl;
 
-// OJO to fail cleanly while doing a realloc
-// if we can't realloc we are pretty much screwed anyway but
-// it makes the code clearer to not have a bunch of if (!ptr) { printf("..."); exit(1); };
-inline void * urealloc(void *ptr, size_t size){
+    tags_blen = bits(max_tag);
+    tags_len = (uint)npar;
+    tags_fix = new uint[uint_len(tags_blen,tags_len)];
+    for(uint i=0;i<(uint)npar;i++)
+       set_field(tags_fix,tags_blen,i,tags[i]);
 
-  void * dest = realloc(ptr,size);
-  //don't fail if we requested size 0
-  if (dest == NULL && size > 0 )
-    throw std::bad_alloc();
-  return dest;
+    delete bmb;    
+    free(tags);
+    tags = NULL;
+    
+    Text = (TextCollection*) TC;
 
-}
 
-inline void * ucalloc(size_t nmemb, size_t size){
+    EBVector = new static_bitsequence_rrr02(empty_texts_bmp,npar,32);
+    free(empty_texts_bmp);
+    empty_texts_bmp = NULL;
 
-  void * dest = calloc(nmemb,size);
-  //don't fail if we requested size 0
-  if (dest == NULL && nmemb > 0 && size > 0 )
-    throw std::bad_alloc();
-  return dest;
+    
+    disable_tc = dis_tc;
+ }
 
-}
 
-inline void * umalloc(size_t size){
-  void * dest = malloc(size);
-  if (dest == NULL && size > 0)
-    throw std::bad_alloc();
-  return dest;
-}
+// ~XMLTree: frees memory of XML tree.
+XMLTree::~XMLTree() 
+ { 
+    int i;
 
-// Save: saves XML tree data structure to file. 
-void XMLTree::Save(unsigned char *filename) 
+    destroyTree(Par);
+    free(Par); // frees the memory of struct Par
+   
+    delete tIdMap;
+    tIdMap = NULL;
+    
+    delete TagName;
+    TagName = NULL;
+    
+    delete Tags;
+    Tags = NULL;
+
+    delete Text; 
+    Text = NULL;
+
+    delete EBVector;
+    EBVector = NULL;
+
+
+ }
+
+
+void XMLTree::print_stats() 
  {
+    uint total_space = Tags->size()+sizeof(static_sequence*);
+    total_space += sizeof(uint*)+sizeof(uint)*(2+uint_len(tags_blen,tags_len));
+    cout << "Space usage for XMLTree:" << endl
+         << " - tags static_sequence: " << Tags->size()+sizeof(static_sequence*) << endl
+         << " - tags access array:    " << sizeof(uint*)+sizeof(uint)*(2+uint_len(tags_blen,tags_len)) << endl
+         << " ... add Diego structures ... " << endl
+         << " *total* " << total_space << endl;
+ }
 
+// Save: saves XML tree data structure to file. 
+void XMLTree::Save(int fd) 
+ {
     FILE *fp;
     char filenameaux[1024];
     int i;
-   
-    sprintf(filenameaux, "%s.srx", filename);
-    fp = fopen(filenameaux, "w");
-    if (fp == NULL) {
-       printf("Error: cannot create file %s to store the tree structure of XML collection\n", filenameaux);
-       exit(1);
-    } 
-    
+
+    fp = fdopen(fd, "wa");
     // first stores the tree topology
     saveTree(Par, fp);
- 
+
     // stores the table with tag names
-    ufwrite(&ntagnames, sizeof(int), 1, fp);
-    for (i=0; i<ntagnames;i++)
-      fprintf(fp, "%s\n",TagName[i]);
-    
-    
-    // stores the flags
-    ufwrite(&indexing_empty_texts, sizeof(bool), 1, fp);
-    ufwrite(&initialized, sizeof(bool), 1, fp);
-    ufwrite(&finished, sizeof(bool), 1, fp);
-    ufwrite(&disable_tc, sizeof(bool),1,fp);
-    
-    if (!indexing_empty_texts) EBVector->save(fp);
+    int ntags = TagName->size();
+
+    ufwrite(&ntags, sizeof(int), 1, fp);
+    for (i = 0; i<ntags;i++)
+      fprintf(fp, "%s\n",TagName->at(i).c_str());
     
+
     // stores the tags
     Tags->save(fp);
+    ufwrite(&tags_blen,sizeof(uint),1,fp);
+    ufwrite(&tags_len,sizeof(uint),1,fp);
+    ufwrite(tags_fix,sizeof(uint),uint_len(tags_blen,tags_len),fp);
 
+    // flags 
+    ufwrite(&disable_tc, sizeof(bool),1,fp);
+    
+    //text positions
+    EBVector->save(fp);
+    
     // stores the texts   
-    if (!disable_tc)
+    if (!disable_tc) {
       Text->Save(fp);
-    if (!disable_tc){
-    int st = CachedText.size();
-    ufwrite(&st, sizeof(int),1,fp);
-    for (int i = 0; i< CachedText.size(); ++i){
-      st = CachedText.at(i).size();
-      ufwrite(&st, sizeof(int),1,fp);
-      ufwrite(CachedText.at(i).c_str(),sizeof(char),(1+strlen(CachedText.at(i).c_str())),fp);
-    };
     };
-    fclose(fp);
+
 
  }
 
 
 // Load: loads XML tree data structure from file. Returns
 // a pointer to the loaded data structure
-XMLTree *XMLTree::Load(unsigned char *filename, int sample_rate_text) 
+XMLTree *XMLTree::Load(int fd) 
  {
-
     FILE *fp;
     char buffer[1024];
     XMLTree *XML_Tree;
     int i;
-    size_t s_tree = 0;
-    long s_text = 0;
-    size_t s_tags = 0;
-
-    // first load the tree topology
-    sprintf(buffer, "%s.srx", filename);
-    fp = fopen(buffer, "r");
-    if (fp == NULL) {
-       printf("Error: cannot open file %s to load the tree structure of XML collection\n", buffer);
-       exit(1);
-    } 
 
-    XML_Tree = new XMLTree();
 
+
+    fp = fdopen(fd, "r");
+
+    XML_Tree = new XMLTree();
+    STARTTIMER();
+    // Load the tree structure
     XML_Tree->Par = (bp *)umalloc(sizeof(bp));
 
     loadTree(XML_Tree->Par, fp); 
+    STOPTIMER(Loading);
+    PRINTTIME("Loading parenthesis struct", Loading);
+    STARTTIMER();
 
-    s_tree += sizeof(bp);
-
-    // stores the table with tag names
-    ufread(&XML_Tree->ntagnames, sizeof(int), 1, fp);
+    XML_Tree->TagName = new vector<string>();
+    XML_Tree->tIdMap = new std::unordered_map<string,int>();
     
-    s_tree += sizeof(int);
-
-    XML_Tree->TagName = (unsigned char **)umalloc(XML_Tree->ntagnames*sizeof(unsigned char *));
+    string s;
+    int ntags;
     
-    s_tags += sizeof(unsigned char*)*XML_Tree->ntagnames;
-
+    // Load the tag names
+    ufread(&ntags, sizeof(int), 1, fp);
 
-    for (i=0; i<XML_Tree->ntagnames;i++) {
-      
-      // OJO Kim is it needed ?
-      int k = feof(fp);
-
-      
-       // fscanf chokes on "\n" which is the case for the root element
-       char * r = fgets(buffer,1023,fp);
-       //       int r = fscanf(fp, "%s\n",buffer);
+    for (i=0; i<ntags;i++) {
+      char * r = fgets(buffer,1023,fp);
        if (r==NULL)
 	 throw "Cannot read tag list";
+       s = (const char*) buffer;
+       // remove the trailing \n
+       s.erase(s.size()-1);       
+       XML_Tree->TagName->push_back(s);
+       XML_Tree->tIdMap->insert(std::make_pair(s,i));
+       
+    };
+    STOPTIMER(Loading);
+    PRINTTIME("Loading tag names struct", Loading);
+    STARTTIMER();
 
-       // strlen is actually the right size, since there is a trailing '\n'
-       int len = strlen((const char*)buffer);
-       XML_Tree->TagName[i] = (unsigned char *)ucalloc(len,sizeof(char));
-       strncpy((char *)XML_Tree->TagName[i], (const char *)buffer,len - 1);
-       s_tags+= len*sizeof(char);
-    }
-	
-    // loads the flags
+    // loads the tag structure
+    XML_Tree->Tags = static_sequence::load(fp);
+    ufread(&XML_Tree->tags_blen,sizeof(uint),1,fp);
+    ufread(&XML_Tree->tags_len,sizeof(uint),1,fp);
+    XML_Tree->tags_fix = new uint[uint_len(XML_Tree->tags_blen,XML_Tree->tags_len)];
+    ufread(XML_Tree->tags_fix,sizeof(uint),uint_len(XML_Tree->tags_blen,XML_Tree->tags_len),fp);
+
+    // TODO ask francisco about this
+    /// FIXME:UGLY tests!
+    uint * seq = new uint[XML_Tree->tags_len];
+    for(uint i=0;i<XML_Tree->tags_len;i++)
+      seq[i] = get_field(XML_Tree->tags_fix,XML_Tree->tags_blen,i);
+    //cout << "Tags test: " << XML_Tree->Tags->test(seq,XML_Tree->tags_len) << endl;
+    XML_Tree->Tags->test(seq,XML_Tree->tags_len);
+    delete [] seq;
+    /// End ugly tests
+    
+    STOPTIMER(Loading);
+    PRINTTIME("Loading tag struct", Loading);
+    STARTTIMER();
 
-    ufread(&(XML_Tree->indexing_empty_texts), sizeof(bool), 1, fp);
-    ufread(&(XML_Tree->initialized), sizeof(bool), 1, fp);
-    ufread(&(XML_Tree->finished), sizeof(bool), 1, fp);
-    ufread(&(XML_Tree->disable_tc), sizeof(bool), 1, fp);
+    // loads the flags
     
-    s_tree+=sizeof(bool)*4;
+    ufread(&(XML_Tree->disable_tc), sizeof(bool), 1, fp);
 
-    if (!(XML_Tree->indexing_empty_texts)) XML_Tree->EBVector = static_bitsequence_rrr02::load(fp);
-    
-    s_tree+= XML_Tree->EBVector->size();
-    
-    // loads the tags
-    XML_Tree->Tags = static_sequence::load(fp);
-    s_tree+= XML_Tree->Tags->size();
+    XML_Tree->EBVector = static_bitsequence_rrr02::load(fp);
 
-    s_text = ftell(fp);
 
+    STOPTIMER(Loading);
+    PRINTTIME("Loading text bitvector struct", Loading);
+    STARTTIMER();
+
+    // Not used  
+    int sample_rate_text = 64;
     // loads the texts
     if (!XML_Tree->disable_tc){
-      XML_Tree->Text = TextCollection::InitTextCollection(sample_rate_text);
-      XML_Tree->Text->Load(fp,sample_rate_text);
-      int sst;
-      int st;
-      ufread(&sst, sizeof(int),1,fp);
-      for (int i=0;i<sst;i++){
-	ufread(&st, sizeof(int),1,fp);
-	char* str = (char*) malloc(sizeof(char)*st+1);
-	ufread(str,sizeof(char),st+1,fp);
-	string cppstr = str;
-	XML_Tree->CachedText.push_back(cppstr);
-	free(str);
-      };
-
+      XML_Tree->Text = TextCollection::Load(fp,sample_rate_text);
     }
-    else
-      XML_Tree->Text = NULL;
+    else XML_Tree->Text = NULL;
+    STOPTIMER(Loading);
+    PRINTTIME("Loading TextCollection", Loading);
+    STARTTIMER();
 
-    s_text = ftell(fp) - s_text;
-
-    
-
-
-    fclose(fp);
-
-    std::cerr << "Tree part is " << s_tree/1024 << " Kbytes,\n"
-	      << "with node->tagid part " << XML_Tree->Tags->size()/1024 << "Kbytes \n"
-	      << "size of Tag part : " << XML_Tree->Tags->length () << " elements\n"
-	      << "sizof(unsigned int)* " <<  XML_Tree->Tags->length () << " = " << 
-      sizeof(unsigned int) * XML_Tree->Tags->length () / 1024 << " Kbytes\n"
-	      << "Tag part is " << s_tags/1024 << " Kbytes,\n"
-	      << "Text collection is " << s_text/1024 << " Kbytes \n";
     return XML_Tree;
  }
 
 
-// ~XMLTree: frees memory of XML tree.
-XMLTree::~XMLTree() 
- { 
-    int i;
-
-    destroyTree(Par);
-    free(Par); // frees the memory of struct Par
-   
-    for (i=0; i<ntagnames;i++) 
-       free(TagName[i]);
-    
-    free(TagName);
-
-    if (!indexing_empty_texts) {
-       //EBVector->~static_bitsequence_rrr02();
-       delete EBVector;
-       EBVector = NULL;
-    }
-
-    //Tags->~static_sequence_wvtree();
-    delete Tags;
-    Tags = NULL;
-
-    //Text->~TextCollection();
-    delete Text;
-    Text = NULL;
-
-    initialized = false;
-    finished = false;
- }
-
 // root(): returns the tree root.
-treeNode XMLTree::Root() 
+inline treeNode XMLTree::Root() 
  {
-    if (!finished) {
-       fprintf(stderr, "Root() : Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-    return root_node(Par);
+   return 0; //root_node(Par);
  }
 
 // SubtreeSize(x): the number of nodes (and attributes) in the subtree of node x.
 int XMLTree::SubtreeSize(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
     return subtree_size(Par, x);
  }
 
 // SubtreeTags(x,tag): the number of occurrences of tag within the subtree of node x.
 int XMLTree::SubtreeTags(treeNode x, TagType tag) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
     if (x == Root())
       x = first_child(Par,x);
     
@@ -311,57 +331,39 @@ bool XMLTree::IsLeaf(treeNode x)
 // IsAncestor(x,y): returns whether node x is ancestor of node y.
 bool XMLTree::IsAncestor(treeNode x, treeNode y) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     return is_ancestor(Par, x, y);
  }
 
 // IsChild(x,y): returns whether node x is parent of node y.
 bool XMLTree::IsChild(treeNode x, treeNode y) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     if (!is_ancestor(Par, x, y)) return false;
     return depth(Par, x) == (depth(Par, y) + 1);
  }
 
+// IsFirstChild(x): returns whether node x is the first child of its parent.
+bool XMLTree::IsFirstChild(treeNode x)
+ {
+    return ((x != NULLT)&&(x==Root() || prev_sibling(Par,x) == (treeNode)-1));
+ }
+
+
 // NumChildren(x): number of children of node x. Constant time with the data structure
 // of Sadakane.
 int XMLTree::NumChildren(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     return degree(Par, x);
  }
 
 // ChildNumber(x): returns i if node x is the i-th children of its parent.
 int XMLTree::ChildNumber(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     return child_rank(Par, x);
  }
 
 // Depth(x): depth of node x, a simple binary rank on the parentheses sequence.
 int XMLTree::Depth(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     return depth(Par, x);
  }
 
@@ -369,11 +371,6 @@ int XMLTree::Depth(treeNode x)
 // nodes (i.e., tags, it disregards the texts in the tree).
 int XMLTree::Preorder(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     return preorder_rank(Par, x);
  }
 
@@ -381,60 +378,44 @@ int XMLTree::Preorder(treeNode x)
 // nodes (i.e., tags, it disregards the texts in the tree).
 int XMLTree::Postorder(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
     return postorder_rank(Par, x);
  }
 
 // Tag(x): returns the tag identifier of node x.
 TagType XMLTree::Tag(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-    
-    return Tags->access(node2tagpos(x));
+    return get_field(tags_fix,tags_blen,node2tagpos(x));
  }
 
 // DocIds(x): returns the range of text identifiers that descend from node x.
 // returns {NULLT, NULLT} when there are no texts descending from x.
 range XMLTree::DocIds(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     range r;
-    if (indexing_empty_texts) { // faster, no rank needed
-       r.min = x;
-       r.max = x+2*subtree_size(Par, x)-2;
+    if (x == NULLT) {
+       r.min = NULLT;
+       r.max = NULLT;
+       return r;
+    };
+        
+    
+    int min = EBVector->rank1(x-1);                          
+    int max = EBVector->rank1(x+2*subtree_size(Par, x)-2); 
+    if (min==max) { // range is empty, no texts within the subtree of x
+      r.min = NULLT;
+      r.max = NULLT;
     }
-    else { // we are not indexing empty texts, we need rank
-       int min = EBVector->rank1(x-1);                          
-       int max = EBVector->rank1(x+2*subtree_size(Par, x)-2); 
-       if (min==max) { // range is empty, no texts within the subtree of x
-          r.min = NULLT;
-          r.max = NULLT;
-       }
-       else { // the range is non-empty, there are texts within the subtree of x
-          r.min = min+1;
-          r.max = max;
-       }
+    else { // the range is non-empty, there are texts within the subtree of x
+      r.min = min+1;
+      r.max = max;
     }
     return r;
+
  }
 
 // Parent(x): returns the parent node of node x.
 treeNode XMLTree::Parent(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
     if (x == Root())
       return NULLT;
     else
@@ -444,127 +425,153 @@ treeNode XMLTree::Parent(treeNode x)
 // Child(x,i): returns the i-th child of node x, assuming it exists.
 treeNode XMLTree::Child(treeNode x, int i) 
 {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
     if (i <= OPTD) return naive_child(Par, x, i);
     else return child(Par, x, i);
- }
+}
 
 // FirstChild(x): returns the first child of node x, assuming it exists. Very fast in BP.
 treeNode XMLTree::FirstChild(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
+   NULLT_IF(x==NULLT);
+   return first_child(Par, x);
+ }
+
+treeNode XMLTree::FirstElement(treeNode x) 
+ {
+   NULLT_IF(x==NULLT);
+   treeNode fc = first_child(Par, x);
+   //<$> is 2
+   return ((fc == NULLT || Tag(fc) != PCDATA_TAG_ID) ? fc : next_sibling(Par,fc));
+
+ }
+
+treeNode XMLTree::NextElement(treeNode x) 
+{
+   NULLT_IF(x==NULLT);
+   treeNode ns = next_sibling(Par, x);
+   return ((ns == NULLT || Tag(ns) != PCDATA_TAG_ID) ? ns : next_sibling(Par,ns));
+}
 
-    return first_child(Par, x);
+// LastChild(x): returns the last child of node x.
+treeNode XMLTree::LastChild(treeNode x)
+ {
+   NULLT_IF(x==NULLT || x == Root() || isleaf(Par,x));
+   return find_open(Par, find_close(Par, x)-1);
  }
 
+
 // NextSibling(x): returns the next sibling of node x, assuming it exists.
 treeNode XMLTree::NextSibling(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-    if (x == Root())
-      return NULLT;
- 
-    return next_sibling(Par, x);
+   NULLT_IF(x==NULLT || x == Root() );
+   return next_sibling(Par, x);
  }
 
 // PrevSibling(x): returns the previous sibling of node x, assuming it exists.
 treeNode XMLTree::PrevSibling(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
-    return prev_sibling(Par, x);
+   NULLT_IF(x==NULLT || x == Root());
+   return prev_sibling(Par, x);
  }
 
-// TaggedChild(x,i,tag): returns the i-th child of node x tagged tag, or NULLT if there is none.
+// TaggedChild(x,tag): returns the first child of node x tagged tag, or NULLT if there is none.
 // Because of the balanced-parentheses representation of the tree, this operation is not supported
 // efficiently, just iterating among the children of node x until finding the desired child.
-treeNode XMLTree::TaggedChild(treeNode x, int i, TagType tag) 
+treeNode XMLTree::TaggedChild(treeNode x, TagType tag) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
-    treeNode child;
    
-    child = first_child(Par, x); // starts at first child of node x
-    if (child==(treeNode)-1) return NULLT; // node x is a leaf, there is no such child
-    while (child!=(treeNode)-1) {
-       if (Tags->access(node2tagpos(child)) == tag) { // current child is labeled with tag of interest
-          i--;
-          if (i==0) return child; // we have seen i children of x tagged tag, this is the one we are looking for
-       }
-       child = next_sibling(Par, x); // OK, let's try with the next child
-    }
-    return NULLT; // no such child was found  
+   NULLT_IF(x==NULLT || isleaf(Par,x));
+
+   treeNode child;   
+   child = first_child(Par, x); // starts at first child of node x
+   if (get_field(tags_fix,tags_blen,node2tagpos(child)) == tag)
+     return child;
+   else
+     return TaggedFollSibling(child,tag);
+ }
+
+// TaggedSibling(x,tag): returns the first sibling of node x tagged tag, or NULLT if there is none.
+treeNode XMLTree::TaggedFollSibling(treeNode x, TagType tag)
+{
+  NULLT_IF(x==NULLT);
+  treeNode sibling = next_sibling(Par, x); 
+  while (sibling != NULLT) {
+    if (get_field(tags_fix,tags_blen,node2tagpos(sibling)) == tag) // current sibling is labeled with tag of interest
+      return sibling; 
+    sibling = next_sibling(Par, sibling); // OK, let's try with the next sibling
+  }
+  return NULLT; // no such sibling was found   
+}
+
+treeNode XMLTree::SelectChild(treeNode x, std::unordered_set<int> *tags)
+{
+  
+  NULLT_IF(x==NULLT || isleaf(Par,x));
+  int i;
+  treeNode child = first_child(Par, x);  
+  TagType t = get_field(tags_fix, tags_blen, node2tagpos(child));
+  std::unordered_set<int>::const_iterator tagit = tags->find(t);
+  if (tagit != tags->end()) return child;  
+  return SelectFollSibling(child,tags);
+}
+
+
+treeNode XMLTree::SelectFollSibling(treeNode x, std::unordered_set<int> *tags)
+{
+
+   NULLT_IF(x==NULLT);
+   int i;
+   TagType t;
+   treeNode sibling = next_sibling(Par, x);
+   std::unordered_set<int>::const_iterator tagit;
+   while (sibling != NULLT) {
+     t = get_field(tags_fix, tags_blen, node2tagpos(sibling));
+     tagit = tags->find(t);
+     if (tagit != tags->end()) return sibling;
+     sibling = next_sibling(Par, sibling);
+   }
+   return NULLT;    
  }
 
+
 // TaggedDesc(x,tag): returns the first node tagged tag with larger preorder than x and within
 // the subtree of x. Returns NULLT if there is none.
 treeNode XMLTree::TaggedDesc(treeNode x, TagType tag) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
+   NULLT_IF(x==NULLT || isleaf(Par,x));
 
-    int r, s;
-    treeNode y;
-    if (isleaf(Par,x))
-      return NULLT;
+   int s = (int) Tags->select_next(tag,node2tagpos(x));
+   NULLT_IF (s == -1);
 
-    r = (int) Tags->rank(tag, node2tagpos(x));
-    s = (int) Tags->select(tag, r+1);
-    if (s == -1) return NULLT; // there is no such node
-    y = tagpos2node(s); // transforms the tag position into a node position
-    if (!is_ancestor(Par, x, y)) return NULLT; // the next node tagged tag (in preorder) is not within the subtree of x.
-    else return y;
+   treeNode y = tagpos2node(s); // transforms the tag position into a node position
+   
+   return (is_ancestor(Par,x,y) ? y : NULLT);
  }
 
-// TaggedNext(x,tag): returns the first node tagged tag with larger preorder than x 
-// Returns NULLT if there is none.
-treeNode XMLTree::TaggedNext(treeNode x, TagType tag) 
- {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
-    int r, s;
-    treeNode y;
-    if (x==NULLT)
-      return NULLT;
 
-    r = (int) Tags->rank(tag, node2tagpos(x));
-    s = (int) Tags->select(tag, r+1);
-    if (s == -1) return NULLT; // there is no such node
-    y = tagpos2node(s); // transforms the tag position into a node position  
-    return (y<=x ? NULLT : y);
+treeNode XMLTree::SelectDesc(treeNode x, std::unordered_set<int> *tags)
+ {
+   NULLT_IF (x ==NULLT || isleaf(Par,x));
+   int i;
+   treeNode min = NULLT;
+   treeNode fc = first_child(Par,x);
+   treeNode aux;
+   std::unordered_set<int>::const_iterator tagit;
+   for (tagit = tags->begin(); tagit != tags->end(); tagit++) {
+     aux = TaggedDesc(x, (TagType) *tagit);
+     if (aux == fc) return fc;
+     if (aux == NULLT) continue;
+     if ((min == NULLT) || (aux < min)) min = aux;
+   };
+   return min;
  }
 
 
+
 // TaggedPrec(x,tag): returns the first node tagged tag with smaller preorder than x and not an
 // ancestor of x. Returns NULLT if there is none.
 treeNode XMLTree::TaggedPrec(treeNode x, TagType tag) 
- {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-    
+ {    
     int r, s;
     treeNode node_s, root;
     r = (int)Tags->rank(tag, node2tagpos(x)-1);
@@ -581,103 +588,109 @@ treeNode XMLTree::TaggedPrec(treeNode x, TagType tag)
     return NULLT; // there is no such node 
  }
 
+
 // TaggedFoll(x,tag): returns the first node tagged tag with larger preorder than x and not in
 // the subtree of x. Returns NULLT if there is none.
-treeNode XMLTree::TaggedFoll(treeNode x, TagType tag) 
+treeNode XMLTree::TaggedFoll(treeNode x, TagType tag)
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
+   NULLT_IF (x ==NULLT || x == Root());
+   
+   return tagpos2node(Tags->select_next(tag,find_close(Par, x)));
 
-    int r, s;
-    if (x ==NULLT || x == Root()|| (next_sibling(Par,x) == -1 ))
-      return NULLT;
+ } 
 
-    r = (int) Tags->rank(tag, node2tagpos(next_sibling(Par, x))-1);
-    s = (int) Tags->select(tag, r+1);  // select returns -1 in case that there is no r+1-th tag.
-    if (s==-1) return NULLT;
-    else return tagpos2node(s);
- }
+// TaggedFollBelow(x,tag,root): returns the first node tagged tag with larger preorder than x 
+// and not in the subtree of x. Returns NULLT if there is none.
+treeNode XMLTree::TaggedFollBelow(treeNode x, TagType tag, treeNode root)
+{
+
+  NULLT_IF (x == NULLT || x == Root());
+  
+  treeNode s = tagpos2node(Tags->select_next(tag, find_close(Par, x)));
+  
+  if (root == Root()) return s;
+  NULLT_IF (s == NULLT || s >= find_close(Par, root));
+  
+  return s;
+} 
 
-// PrevText(x): returns the document identifier of the text to the left 
-// of node x, or NULLT if x is the root node or the text is empty.
-// Assumes Doc ids start from 0.
-DocID XMLTree::PrevText(treeNode x) 
+/* Here we inline TaggedFoll to find the min globally, and only at the end
+   we check if the min is below the context node */
+treeNode XMLTree::SelectFollBelow(treeNode x, std::unordered_set<int> *tags, treeNode root)
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
 
-    if (x == Root()) return NULLT;
-    if (indexing_empty_texts)  // faster, no rank needed
-       return (DocID)x-1;
-    else { // we are not indexing empty texts, rank is needed
-       if (EBVector->access(x-1) == 0) 
-          return (DocID)NULLT;  // there is no text to the left of node (text is empty)
-       else
-          return (DocID)EBVector->rank1(x-1)-1;  //-1 because document ids start from 0
-    }
+   NULLT_IF(x==NULLT || x==Root());
+   int i;
+   treeNode min = NULLT;
+   treeNode ns = next_sibling(Par, x);
+   treeNode aux;
+   std::unordered_set<int>::const_iterator tagit;
+   for (tagit = tags->begin(); tagit != tags->end(); tagit++) {
+
+     aux = tagpos2node(Tags->select_next(*tagit, find_close(Par, x)));
+     
+     // The next sibling of x is guaranteed to be below ctx
+     // and is the node with lowest preorder which is after ctx.
+     // if we find it, we return early;
+     
+     if (aux == ns ) return ns;
+     if (aux == NULLT) continue;
+     if ((min == NULLT) || (aux < min)) min = aux;
+   };
+     
+   // found the smallest node in preorder which is after x.
+   // if ctx is the root node, just return what we found.
+
+   if (root == Root()) return min;
+   // else check whether if is in below the ctx node
+
+   NULLT_IF (min == NULLT || min >= find_close(Par, root));
+   
+   return min;
+   
  }
 
-// NextText(x): returns the document identifier of the text to the right
-// of node x, or NULLT if x is the root node. Assumes Doc ids start from 0.
-DocID XMLTree::NextText(treeNode x) 
- {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
 
-    if (x == Root()) return NULLT;
-    if (indexing_empty_texts)  // faster, no rank needed
-       return (DocID)x+2*subtree_size(Par, x)-1;
-    else { // we are not indexing empty texts, rank is needed
-       int p = x+2*subtree_size(Par, x)-1;
-       if (EBVector->access(p) == 0) // there is no text to the right of node
-          return (DocID)NULLT;
-       else
-          return (DocID)EBVector->rank1(p)-1; //-1 because document ids start from 0
+// TaggedAncestor(x, tag): returns the closest ancestor of x tagged tag. Return
+// NULLT is there is none.
+treeNode XMLTree::TaggedAncestor(treeNode x, TagType tag)
+ {    
+    if (x == NULLT || x == Root())
+       return NULLT;
+    
+    treeNode s = parent(Par, x), r = Root();
+    while (s != r) {
+       if (get_field(tags_fix,tags_blen,node2tagpos(s)) /*Tags->access(node2tagpos(s))*/ == tag) return s;
+       s = parent(Par, s);
     }
+    return NULLT;
  }
 
+
+
 // MyText(x): returns the document identifier of the text below node x, 
 // or NULLT if x is not a leaf node or the text is empty. Assumes Doc 
 // ids start from 0.
 DocID XMLTree::MyText(treeNode x) 
- {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
+{
+  TagType tag = Tag(x);
+  // seems faster than testing EBVector->access(x);
 
-    if (!IsLeaf(x)) return NULLT;
-    if (indexing_empty_texts) // faster, no rank needed
-       return (DocID)x;
-    else { // we are not indexing empty texts, rank is needed
-       if (EBVector->access(x) == 0)  // there is no text below node x
-          return (DocID)NULLT;
-       else
-          return (DocID)EBVector->rank1(x)-1; //-1 because document ids start from 0
-    } 
- }
+  if (tag == PCDATA_TAG_ID || tag == ATTRIBUTE_DATA_TAG_ID)
+    return (DocID) (EBVector->rank1(x)-1); //-1 because document ids start from 0
+  else 
+    return (DocID) NULLT;
+  
+}
 
 // TextXMLId(d): returns the preorder of document with identifier d in the tree consisting of
 // all tree nodes and all text nodes. Assumes that the tree root has preorder 1.
 int XMLTree::TextXMLId(DocID d) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
-    if (indexing_empty_texts) 
-       return d + rank_open(Par, d)+1; // +1 because root has preorder 1
-    else { // slower, needs rank and select
-       int s = EBVector->select1(d+1);
-       return rank_open(Par, s) + d + 1; // +1 because root has preorder 1
-    }
+   NULLT_IF(d == NULLT);
+     int s = EBVector->select1(d+1);
+   return rank_open(Par, s) + d + 1; // +1 because root has preorder 1
+   
  }
 
 // NodeXMLId(x): returns the preorder of node x in the tree consisting 
@@ -685,300 +698,27 @@ int XMLTree::TextXMLId(DocID d)
 // preorder 0;
 int XMLTree::NodeXMLId(treeNode x) 
  {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-
-    if (indexing_empty_texts)
-       return x - 1 + rank_open(Par, x);
-    else {
-       if (x == Root()) return 1; // root node has preorder 1
-       else
-          return rank_open(Par, x) + EBVector->rank1(x-1);
-    }
+   NULLT_IF(x == NULLT);
+   if (x == Root()) return 1; // root node has preorder 1
+   return rank_open(Par, x) + EBVector->rank1(x-1);
  }
 
 // ParentNode(d): returns the parent node of document identifier d.
 treeNode XMLTree::ParentNode(DocID d) 
- {
-    if (!finished) {
-       fprintf(stderr, "Error: data structure has not been constructed properly\n");
-       exit(1);
-    }
-    
-    if (d == NULLT)
-      return NULLT;
-    
-    int s;
-    // OJO : Kim : I added the d+1. before that, else branch was 
-    // EBVector->select1(d)
-    // and gave wrong results (I'm really poking a bear with a stick here).
-    if (indexing_empty_texts) s = d;
-    else s = EBVector->select1(d+1);
-    
-    if (inspect(Par,s) == CP) // is a closing parenthesis
-       return parent(Par, find_open(Par, s));
-    else // is an opening parenthesis
-       return (treeNode)s;
-     
- }
-
-
-// OpenDocument(empty_texts): it starts the construction of the data structure for
-// the XML document. Parameter empty_texts indicates whether we index empty texts
-// in document or not. Returns a non-zero value upon success, NULLT in case of error.
-int XMLTree::OpenDocument(bool empty_texts, int sample_rate_text,bool dtc)
- {
-    initialized = true;
-    finished = false;
-    found_attributes = false;
-    npar = 0;
-    parArraySize = 1;
-    ntagnames = 2;    
-    disable_tc = dtc;
-    
-    indexing_empty_texts = empty_texts;
-    
-    par_aux = (pb *)umalloc(sizeof(pb)*parArraySize);
-    
-    tags_aux = (TagType *) umalloc(sizeof(TagType));
-    
-    TagName = (unsigned char **) umalloc(2*sizeof(unsigned char*));
-
-    TagName[0] = (unsigned char *) umalloc(4*sizeof(unsigned char));
-
-    strcpy((char *) TagName[0], "<@>");
-
-    TagName[1] = (unsigned char *) umalloc(4*sizeof(unsigned char));
-
-    strcpy((char *) TagName[1], "<$>");
-
-
-    if (!indexing_empty_texts) 
-      empty_texts_aux = (unsigned int *)umalloc(sizeof(unsigned int));
-       
-    
-    
-    Text = TextCollection::InitTextCollection((unsigned)sample_rate_text);
-    
-    return 1;  // indicates success in the initialization of the data structure
- }
-
-// CloseDocument(): it finishes the construction of the data structure for the XML
-// document. Tree and tags are represented in the final form, dynamic data 
-// structures are made static, and the flag "finished" is set to true. After that, 
-// the data structure can be queried.
-int XMLTree::CloseDocument()
- {
-    if (!initialized) {  // data structure has not been initialized properly
-       fprintf(stderr, "Error: data structure has not been initialized properly (by calling method OpenDocument)\n");
-       return NULLT;
-    }
-    
-    // closing parenthesis for the tree root
-    par_aux = (pb *)urealloc(par_aux, sizeof(pb)*(1+npar/(8*sizeof(pb))));
-    
-    // creates the data structure for the tree topology
-    Par = (bp *)umalloc(sizeof(bp));
-    bp_construct(Par, npar, par_aux, OPT_DEGREE|0);    
-    // creates structure for tags
-    static_bitsequence_builder * bmb = new static_bitsequence_builder_brw32(20);
-    static_permutation_builder * pmb = new static_permutation_builder_mrrr(PERM_SAMPLE, bmb);
-    static_sequence_builder * ssb = new static_sequence_builder_gmr_chunk(bmb, pmb);
-
-
-    // If we found an attribute then "<@>" is present in the tree
-    // if we didn't then it is not. "<$>" is never present in the tree
-    int ntagsize = found_attributes ? 2*ntagnames-1 : 2*ntagnames - 2;
-
-    Tags = new static_sequence_gmr((uint *) tags_aux, (uint) npar-1,ntagsize, bmb, ssb);
-    
-    delete bmb;
-    delete pmb;
-    delete ssb;
-    // makes the text collection static
-    if (!disable_tc)
-      Text->MakeStatic();
-    
-    // creates the data structure marking the non-empty texts (just in the case it is necessary)
-    if (!indexing_empty_texts)  {
-       EBVector = new static_bitsequence_rrr02((uint *)empty_texts_aux,(ulong)npar,(uint)32);
-       free (empty_texts_aux);
-       empty_texts_aux = NULL;
-    }
-   
-    // OJO was leaked before, found by valgrind
-    free(tags_aux);
-
-    tags_aux = NULL;
-
-    finished = true;
-
-    return 1; // indicates success in the inicialization
+ {    
+   NULLT_IF (d == NULLT);   
+   return (treeNode) EBVector->select1(d+1);     
  }
 
-
-// NewOpenTag(tagname): indicates the event of finding a new opening tag in the document.
-// Tag name is given. Returns a non-zero value upon success, and returns NULLT
-// in case of failing when trying to insert the new tag.
-int XMLTree::NewOpenTag(unsigned char *tagname)
- {
-    int i;
-
-    if (!initialized) {  // data structure has not been initialized properly
-       fprintf(stderr, "Error: you cannot insert a new opening tag without first calling method OpenDocument first\n");
-       return NULLT;
-    }
-    
-    // inserts a new opening parentheses in the bit sequence
-    if (sizeof(pb)*8*parArraySize == npar) { // no space left for the new parenthesis
-       par_aux = (pb *)urealloc(par_aux, sizeof(pb)*2*parArraySize);
-       parArraySize *= 2;
-    }
-    
-    setbit(par_aux,npar,OP);  // marks a new opening parenthesis
-
-    // transforms the tagname into a tag identifier. If the tag is new, we insert
-    // it in the table.
-    for (i=0; i<ntagnames; i++)
-      if (strcmp((const char *)tagname,(const char *)TagName[i])==0) break;
- 
-
-    // NewOpenTag("<@>") was called
-    if (i==0) 
-      found_attributes=true;
-
-    if (i==ntagnames) { // the tag is a new one, then we insert it
-       TagName = (unsigned char **)urealloc(TagName, sizeof(char *)*(ntagnames+1));
-       
-       if (!TagName) {
-          fprintf(stderr, "Error: not enough memory\n");
-          return NULLT;
-       }
-       
-       ntagnames++;
-       TagName[i] = (unsigned char *)umalloc(sizeof(unsigned char)*(strlen((const char *)tagname)+1));
-       strcpy((char *)TagName[i], (const char *)tagname);
-    } 
-    tags_aux = (TagType *) urealloc(tags_aux, sizeof(TagType)*(npar + 1));
-
-    tags_aux[npar] = i; // inserts the new tag id within the preorder sequence of tags
-    
-    npar++;
-    
-    return 1;
-    
- }
-
-
-// NewClosingTag(tagname): indicates the event of finding a new closing tag in the document.
-// Tag name is given. Returns a non-zero value upon success, and returns NULLT
-// in case of failing when trying to insert the new tag.
-int XMLTree::NewClosingTag(unsigned char *tagname)
- {
-    int i;
-
-    if (!initialized) {  // data structure has not been initialized properly
-       fprintf(stderr, "Error: you cannot insert a new closing tag without first calling method OpenDocument first\n");
-       return NULLT;
-    }
-    
-    // inserts a new closing parentheses in the bit sequence
-    if (sizeof(pb)*8*parArraySize == npar) { // no space left for the new parenthesis
-       par_aux = (pb *)urealloc(par_aux, sizeof(pb)*2*parArraySize);
-       parArraySize *= 2;
-    }
-    
-    setbit(par_aux,npar,CP);  // marks a new closing opening parenthesis
-
-    // transforms the tagname into a tag identifier. If the tag is new, we insert
-    // it in the table.
-    for (i=0; i<ntagnames; i++)
-       if (strcmp((const char *)tagname,(const char *)TagName[i])==0) break;
- 
-    if (i==ntagnames) { // the tag is a new one, then we insert it
-       TagName = (unsigned char **)urealloc(TagName, sizeof(char *)*(ntagnames+1));
-       
-       
-       ntagnames++;
-       TagName[i] = (unsigned char *)umalloc(sizeof(char)*(strlen((const char *)tagname)+2));
-       TagName[i][0] = '/';
-       strcpy((char *)&(TagName[i][1]), (const char *)tagname);
-    } 
-
-    tags_aux = (TagType *)urealloc(tags_aux, sizeof(TagType)*(npar + 1));
-
-    tags_aux[npar] = i; // inserts the new tag id within the preorder sequence of tags
-    
-    npar++;
-
-    return 1; // success
-    
- }
-
-
-// NewText(s): indicates the event of finding a new (non-empty) text s in the document.
-// The new text is inserted within the text collection. Returns a non-zero value upon
-// success, NULLT in case of error.
-int XMLTree::NewText(unsigned char *s)
- {
-    if (!initialized) {  // data structure has not been initialized properly
-       fprintf(stderr, "Error: you cannot insert a new text without first calling method OpenDocument first\n");
-       return NULLT;
-    }
-
-    if (disable_tc) {
-      XMLTree::NewEmptyText();
-      return 1;
-    };
-
-    if (!indexing_empty_texts) {
-       empty_texts_aux = (unsigned int *)urealloc(empty_texts_aux, sizeof(pb)*(1+(npar-1)/(8*sizeof(pb))));
-              bitset(empty_texts_aux, npar-1);  // marks the non-empty text with a 1 in the bit vector
-    }
-    
-    Text->InsertText(s);
-    string cpps = (char*) s;
-    CachedText.push_back(cpps); 
-    
-    return 1; // success
- }
-
-// NewEmptyText(): indicates the event of finding a new empty text in the document.
-// In case of indexing empty and non-empty texts, we insert the empty texts into the
-// text collection. In case of indexing only non-empty texts, it just indicates an
-// empty text in the bit vector of empty texts. Returns a non-zero value upon
-// success, NULLT in case of error.
-int XMLTree::NewEmptyText() 
- {
-    unsigned char c = 0;
-    if (!initialized) {  // data structure has not been initialized properly
-       fprintf(stderr, "Error: you cannot insert a new empty text without first calling method OpenDocument first\n");
-       return NULLT;
-    }
-
-    if (!indexing_empty_texts) {
-       empty_texts_aux = (unsigned int *)urealloc(empty_texts_aux, sizeof(pb)*(1+(npar-1)/(8*sizeof(pb))));
-       
-       bitclean(empty_texts_aux, npar-1);  // marks the empty text with a 0 in the bit vector
-    }
-    else Text->InsertText(&c); // we insert the empty text just in case we index all the texts
-    
-    return 1; // success    
- }
-
-
 // GetTagId: returns the tag identifier corresponding to a given tag name.
 // Returns NULLT in case that the tag name does not exists.
 TagType XMLTree::GetTagId(unsigned char *tagname)
  {
-    int i;
-    // this should be changed for more efficient processing
-    for (i=0; i<ntagnames; i++)
-       if (strcmp((const char *)tagname,(const char *)TagName[i])==0) break; 
-    if (i==ntagnames) return (TagType)NULLT; // tagname does not exists in the table
-    else return i;
+  
+   string s = (char *) tagname;
+   TagIdMapIT it = tIdMap->find(s);    
+   return (TagType) ((it != tIdMap->end()) ? it->second : -1);
+    
  }
 
 
@@ -987,37 +727,37 @@ TagType XMLTree::GetTagId(unsigned char *tagname)
 unsigned char *XMLTree::GetTagName(TagType tagid)
  {
     unsigned char *s;
-
-    if (tagid >= ntagnames) return NULL; // invalid tag identifier
-    s = (unsigned char *)umalloc((strlen((const char *)TagName[tagid])+1)*sizeof(unsigned char));
-    strcpy((char *)s, (const char *)TagName[tagid]);
-    return s;
+    if ( tagid < 0 || tagid >= TagName->size())
+      return (unsigned char *) "<INVALID TAG>";
+    strcpy((char *)s, TagName->at(tagid).c_str());
+    
+    return (s == NULL ? (unsigned char*) "<INVALID TAG>" : s);
  }
 
 
-//KIM : OJO need the two following methods
-
 const unsigned char *XMLTree::GetTagNameByRef(TagType tagid)
  {
-    if (tagid >= ntagnames) return NULL; // invalid tag identifier
-    return ((const unsigned char*)  TagName[tagid]);
+
+   unsigned char *s;
+   if ( tagid < 0 || tagid >= TagName->size())
+     return (unsigned char *) "<INVALID TAG>";
+   
+   return (const unsigned char *) TagName->at(tagid).c_str();
+   
  }
 
 
 
 TagType XMLTree::RegisterTag(unsigned char *tagname)
-{
-  if (!finished)
-    return NULLT;
-  
-  TagType id = XMLTree::GetTagId(tagname);
-  if (id == NULLT){
-    id = ntagnames;
-    ntagnames = ntagnames + 1;    
-    TagName = (unsigned char **) urealloc(TagName,ntagnames*(sizeof(unsigned char*)));
-    TagName[id] = (unsigned char *) umalloc(sizeof(unsigned char)*strlen( (const char*) tagname)+1);
-    strcpy((char*)TagName[id], (const char *)tagname);  
-  };
+ {  
+    TagType id = XMLTree::GetTagId(tagname);
+    if (id == NULLT) {
+      string s = (char *) tagname;      
+      REGISTER_TAG(TagName,tIdMap,s);
+      
+    };
+    
+    return id;
+ }
+
 
-  return id;
-}