--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/find.c	Wed Aug 29 00:19:14 2007 +0200
@@ -0,0 +1,175 @@
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include "dictre.h"
+
+static unsigned char *index;
+static int indexfd;
+static int indexsize;
+static FILE *defs;
+const static char indexname[] = "akcentiga.index";
+const static char dictname[] = "akcentiga.dict";
+
+int get_filesize(const char *fname)
+{
+    struct stat st;
+    int res;
+    res = stat(fname, &st);
+    if (res == -1)
+    {
+        fprintf(stderr, "Problem stating the file %s\n", fname);
+        perror("Error:");
+        exit(-1);
+    }
+
+    return st.st_size;
+}
+
+void init_dictionary()
+{
+    indexsize = get_filesize(indexname);
+    indexfd = open(indexname, O_RDONLY);
+    if (indexfd == -1)
+    {
+        fprintf(stderr, "Problem opening the file %s\n", indexname);
+        perror("Error:");
+        exit(-1);
+    }
+    index = (unsigned char *) mmap(0, indexsize, PROT_READ, MAP_SHARED,
+            indexfd, 0);
+
+    defs = fopen(dictname, "r");
+    if (defs == 0)
+    {
+        fprintf(stderr, "Problem opening the file %s\n", dictname);
+        perror("Error:");
+        exit(-1);
+    }
+}
+
+void end_dictionary()
+{
+    munmap(index, indexsize);
+    close(indexfd);
+    fclose(defs);
+}
+
+static void fill_def(int offset, int length, char * def)
+{
+    fseek(defs, offset, SEEK_SET);
+    fread(def, 1, length, defs);
+}
+
+static int pointer_at_end(unsigned char *ptr)
+{
+    if (ptr >= (index + indexsize))
+        return 1;
+    return 0;
+}
+
+static char * skip_until_newline(char *from)
+{
+    if (pointer_at_end(from))
+        return 0;
+    while(*from != '\n' && *from != 0)
+    {
+        ++from;
+        if(pointer_at_end(from))
+            return 0;
+    }
+    return from;
+}
+
+static int compare(const unsigned char *word, const unsigned char *test)
+{
+    int i;
+
+    /*printf("Comparing %s to %.20s\n", word, test);*/
+    for(i=0; word[i] != 0 && test[i] != 0; ++i)
+    {
+        if (word[i] != test[i])
+        {
+            break;
+        }
+    }
+    if (word[i] == 0 && test[i] == '\t')
+        return 0;
+    else if (word[i] == 0)
+        return -1;
+    else if (test[i] == '\t')
+        return 1;
+    else if (word[i] > test[i])
+        return 1;
+    else if (word[i] < test[i])
+        return -1;
+
+    /* It should never reach this. */
+    return -1;
+}
+
+static char * bin_search(const char *word)
+{
+    int step, pivot;
+
+    pivot = indexsize / 2;
+    step = indexsize / 2;
+
+    do
+    {
+        char *test;
+        int comparision;
+        test = index + pivot;
+        test = skip_until_newline(test);
+        if (test == 0)
+            return 0;
+        test += 1; /* skip exactly the new line */
+
+        comparision = compare(word, test);
+        if (comparision == 0)
+        {
+            return test + strlen(word) + 1; /* skip word and \n */
+        } else if (comparision < 0)
+        {
+            step = step / 2;
+            pivot = pivot - step;
+        } else if (comparision > 0)
+        {
+            step = step / 2;
+            pivot = pivot + step;
+        }
+    } while(step > 0);
+    return 0;
+}
+
+static int my_get_int(char **pos)
+{
+    int i;
+    char *start;
+    int val;
+
+    start = *pos;
+    for(i=0; start[i] != '\t' && start[i] != '\n'; ++i)
+        ;
+    val = str2int_len(start, i);
+    *pos += i + 1;
+    return val;
+}
+
+void find_def(const char *word, char * def)
+{
+    int offset, len;
+    char *pos;
+
+    pos = bin_search(word); /* pos points to the offset already. */
+    if (pos == 0)
+    {
+        def[0] = 0;
+        /*fprintf(stderr, "Cannot find %s\n", word);*/
+        return;
+    }
+    offset = my_get_int(&pos); /* increments pos */
+    len = my_get_int(&pos); /* increments pos */
+    fill_def(offset, len, def);
+}