int create_index_on(TCHAR * file_path)//建立索引的接口 命令行和图形界面通用
{
char mutil_file_path[MAX_PATH]={};
WideCharToMultiByte(CP_OEMCP,NULL,file_path,-1,mutil_file_path,MAX_PATH,NULL,FALSE);
MemoryIndexTree * temp_index=make_memory_index_tree_all_file(file_path,NULL);
THE_NEXT_INDEX * temp_next_index=make_next_index__(temp_index);
char index_file_name[MAX_PATH]={};
strcpy(index_file_name,mutil_file_path);
strcat(index_file_name,INDEX_DB_NAME);
char next_index_file_name[MAX_PATH]={};
strcpy(next_index_file_name,mutil_file_path);
strcat(next_index_file_name,NEXT_INDEX_DB_NAME);
int res=write_buf_to_file(temp_next_index->next_index__,
temp_next_index->length/* 这个地方的length是字节数不是个数*/
,next_index_file_name,"wb");
if (res<=0)
{
printf("二级索引写入失败\n");
}else
{
printf("二级索引写入成功\n");
}
if (write_index_to_file(temp_index,index_file_name,"wb")>0)
{
printf("一级索引写入成功\n");
}
return 0;
}
/*
* Adds a file to the index
*/
index_p add_file(index_p index, char *file) {
// check if file exists and can be read
FILE *f = fopen(file, "r");
if (!f) {
printf("Cannot open %s!\nIndex not updated.\n", file);
return index;
}
fclose(f);
// insert file into file list (alphabetically ordered)
int doc_id = 0;
// always insert temporary search document in the beginning
if (strcmp(file, "._tmp_search_doc")) {
for (doc_id = 0; doc_id < index->nr_docs; doc_id++) {
int cmp = strcmp(index->documents[doc_id].name, file);
if (!cmp) {
printf("%s is already in the filebase.\n", file);
return index;
} else if (0 < cmp) {
// right position in list found
break;
}
}
}
// insert document in list
index = (index_p) realloc(index, sizeof(index_t) + sizeof(indexed_document_t) * (index->nr_docs + 1));
memmove(&index->documents[doc_id+1], &index->documents[doc_id], sizeof(indexed_document_t) * (index->nr_docs - doc_id));
index->documents[doc_id].name = (char *) malloc(strlen(file) + 1);
memcpy(index->documents[doc_id].name, file, strlen(file) + 1);
index->documents[doc_id].nr_words = 0;
index->nr_docs++;
// update indices: increase indices which are greater or equal to doc_id of added document
indexed_word_p w = index->words;
while (w) {
int i;
for (i = 0; i < w->nr_docs; i++) {
if (w->documents[i].id >= doc_id) {
w->documents[i].id++;
}
}
w = w->next;
}
// parse file contents and add words to index
parse_file_for_index(index, file);
write_index_to_file(index);
return index;
}
/*
* Regenerates the index based on the files in the filebase
*/
void rebuild_index(index_p index) {
// clear index but keep filebase
indexed_word_p w;
while ((w = index->words)) {
index->words = w->next;
free(w->stem);
free(w);
}
index->nr_words = 0;
// rescan every document
int i;
for (i = 0; i < index->nr_docs; i++) {
index->documents[i].nr_words = 0;
parse_file_for_index(index, index->documents[i].name);
}
// save
write_index_to_file(index);
}
/*
* Removes a file from index
*/
void remove_file(index_p index, int doc_id) {
// open file or print error message
if (!index->nr_docs) {
printf("Filebase empty!\n");
return;
}
if (doc_id < 0 || doc_id >= index->nr_docs) {
printf("Error: illegal document id. No document removed!\n");
}
// remove document from list in index
free(index->documents[doc_id].name);
memmove(&index->documents[doc_id], &index->documents[doc_id+1], sizeof(indexed_document_t) * (index->nr_docs - 1 - doc_id));
index->nr_docs--;
indexed_word_p w = index->words; // current word
indexed_word_p p = NULL; // previous word
// remove document from the list of each indexed word
while (w) {
// find index of removed document in list (or of first document with higher id)
int i;
int remove = 0;
for (i = 0; i < w->nr_docs; i++) {
if (w->documents[i].id == doc_id) {
w->nr_docs--;
// document found in list, indicate removal
remove = 1;
break;
} else if (w->documents[i].id > doc_id) {
break;
}
}
// reduce document id of all documents with id > removed document id
// and shift array items (in order to remove entry of the document we want to remove) if neccessary
for (; i < w->nr_docs; i++) {
w->documents[i] = w->documents[i+remove];
w->documents[i].id--;
}
if (w->nr_docs == 0) {
// only occurance of this word is in removed document -> remove word from index
if (!p) {
index->words = w->next;
} else {
p->next = w->next;
}
index->nr_words--;
indexed_word_p n = w->next;
free(w->stem);
free(w);
w = n;
} else {
// get next indexed word
p = w;
w = w->next;
}
}
// commit changes to file
write_index_to_file(index);
}
