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-rw-r--r--libibex/file.c383
1 files changed, 383 insertions, 0 deletions
diff --git a/libibex/file.c b/libibex/file.c
new file mode 100644
index 0000000000..e9eaab7f51
--- /dev/null
+++ b/libibex/file.c
@@ -0,0 +1,383 @@
+/*
+ Copyright 2000 Helix Code Inc.
+*/
+
+/* file.c: index file read/write ops */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "ibex_internal.h"
+
+static unsigned long read_number(FILE *f);
+static void write_number(FILE *f, unsigned long n);
+static char *get_compressed_word(FILE *f, char **lastword);
+
+static gint free_file(gpointer key, gpointer value, gpointer data);
+static void free_word(gpointer key, gpointer value, gpointer data);
+
+/* The file format is:
+ *
+ * version string (currently "ibex1")
+ * file count
+ * list of compressed filenames, separated by \0
+ * word count
+ * list of compressed words, each followed by \0, a count, and that
+ * many references.
+ *
+ * All numbers are stored 7-bit big-endian, with the high bit telling
+ * whether or not the number continues to the next byte.
+ *
+ * compressed text consists of a byte telling how many characters the
+ * line has in common with the line before it, followed by the rest of
+ * the string. Obviously this only really works if the lists are sorted.
+ */
+ibex *
+ibex_open(char *file, gboolean create)
+{
+ ibex *ib;
+ FILE *f;
+ char vbuf[sizeof(IBEX_VERSION) - 1];
+ char *word, *lastword;
+ unsigned long nfiles, nwords, nrefs, ref;
+ ibex_file **ibfs = NULL;
+ int i;
+ GPtrArray *refs;
+
+ f = fopen(file, "r");
+ if (!f && (errno != ENOENT || !create))
+ {
+ if (errno == 0)
+ errno = ENOMEM;
+ return NULL;
+ }
+
+ ib = g_malloc(sizeof(ibex));
+ ib->dirty = FALSE;
+ ib->path = g_strdup(file);
+ ib->files = g_tree_new(strcmp);
+ ib->words = g_hash_table_new(g_str_hash, g_str_equal);
+ ib->oldfiles = g_ptr_array_new();
+
+ if (!f)
+ return ib;
+
+ /* Check version. */
+ if (fread(vbuf, 1, sizeof(vbuf), f) != sizeof(vbuf))
+ {
+ if (feof(f))
+ errno = EINVAL;
+ goto errout;
+ }
+ if (strncmp(vbuf, IBEX_VERSION, sizeof(vbuf) != 0))
+ {
+ errno = EINVAL;
+ goto errout;
+ }
+
+ /* Read list of files. */
+ nfiles = read_number(f);
+ ibfs = g_malloc(nfiles * sizeof(ibex_file *));
+ lastword = NULL;
+ for (i = 0; i < nfiles; i++)
+ {
+ ibfs[i] = g_malloc(sizeof(ibex_file));
+ ibfs[i]->name = get_compressed_word(f, &lastword);
+ if (!ibfs[i]->name)
+ goto errout;
+ ibfs[i]->index = 0;
+ g_tree_insert(ib->files, ibfs[i]->name, ibfs[i]);
+ }
+
+ /* Read list of words. */
+ nwords = read_number(f);
+ lastword = NULL;
+ for (i = 0; i < nwords; i++)
+ {
+ word = get_compressed_word(f, &lastword);
+ if (!word)
+ goto errout;
+
+ nrefs = read_number(f);
+ refs = g_ptr_array_new();
+ g_ptr_array_set_size(refs, nrefs);
+ while (nrefs--)
+ {
+ ref = read_number(f);
+ if (ref >= nfiles)
+ goto errout;
+ refs->pdata[nrefs] = ibfs[ref];
+ }
+
+ g_hash_table_insert(ib->words, word, refs);
+ }
+
+ g_free(ibfs);
+ fclose(f);
+ return ib;
+
+errout:
+ fclose(f);
+ g_tree_traverse(ib->files, free_file, G_IN_ORDER, NULL);
+ g_tree_destroy(ib->files);
+ g_hash_table_foreach(ib->words, free_word, NULL);
+ g_hash_table_destroy(ib->words);
+ g_ptr_array_free(ib->oldfiles, TRUE);
+ if (ibfs)
+ g_free(ibfs);
+ g_free(ib->path);
+ g_free(ib);
+
+ return NULL;
+}
+
+struct ibex_write_data {
+ unsigned long index;
+ FILE *f;
+ char *lastname;
+};
+
+static int
+get_prefix(struct ibex_write_data *iwd, char *name)
+{
+ int i = 0;
+ if (iwd->lastname)
+ {
+ while (!strncmp(iwd->lastname, name, i + 1))
+ i++;
+ }
+ iwd->lastname = name;
+ return i;
+}
+
+static gint
+write_file(gpointer key, gpointer value, gpointer data)
+{
+ char *file = key;
+ ibex_file *ibf = value;
+ struct ibex_write_data *iwd = data;
+ int prefix;
+
+ ibf->index = iwd->index++;
+ prefix = get_prefix(iwd, file);
+ fprintf(iwd->f, "%c%s", prefix, file + prefix);
+ fputc(0, iwd->f);
+ return FALSE;
+}
+
+static void
+store_word(gpointer key, gpointer value, gpointer data)
+{
+ GTree *wtree = data;
+
+ g_tree_insert(wtree, key, value);
+}
+
+static gint
+write_word(gpointer key, gpointer value, gpointer data)
+{
+ char *word = key;
+ GPtrArray *refs = value;
+ struct ibex_write_data *iwd = data;
+ ibex_file *ibf;
+ int i, ind, prefix;
+
+ for (i = ind = 0; i < refs->len; i++)
+ {
+ ibf = g_ptr_array_index(refs, i);
+ if (ibf->index == -1)
+ {
+ g_ptr_array_remove_index_fast(refs, i);
+ i--;
+ }
+ else
+ ind++;
+ }
+
+ if (ind != 0)
+ {
+ prefix = get_prefix(iwd, word);
+ fprintf(iwd->f, "%c%s", prefix, word + prefix);
+ fputc(0, iwd->f);
+
+ write_number(iwd->f, ind);
+
+ for (i = 0; i < refs->len; i++)
+ {
+ ibf = g_ptr_array_index(refs, i);
+ write_number(iwd->f, ibf->index);
+ }
+ }
+ return FALSE;
+}
+
+int
+ibex_write(ibex *ib)
+{
+ struct ibex_write_data iwd;
+ GTree *wtree;
+ char *tmpfile;
+
+ tmpfile = g_strdup_printf("%s~", ib->path);
+ iwd.f = fopen(tmpfile, "w");
+ if (!iwd.f)
+ {
+ if (errno == 0)
+ errno = ENOMEM;
+ g_free(tmpfile);
+ return -1;
+ }
+
+ fputs(IBEX_VERSION, iwd.f);
+ if (ferror(iwd.f))
+ goto lose;
+
+ iwd.index = 0;
+ iwd.lastname = NULL;
+ write_number(iwd.f, g_tree_nnodes(ib->files));
+ if (ferror(iwd.f))
+ goto lose;
+ g_tree_traverse(ib->files, write_file, G_IN_ORDER, &iwd);
+ if (ferror(iwd.f))
+ goto lose;
+
+ iwd.lastname = NULL;
+ write_number(iwd.f, g_hash_table_size(ib->words));
+ if (ferror(iwd.f))
+ goto lose;
+ wtree = g_tree_new(strcmp);
+ g_hash_table_foreach(ib->words, store_word, wtree);
+ g_tree_traverse(wtree, write_word, G_IN_ORDER, &iwd);
+ g_tree_destroy(wtree);
+ if (ferror(iwd.f))
+ goto lose;
+
+ if (fclose(iwd.f) == 0 && rename(tmpfile, ib->path) == 0)
+ {
+ g_free(tmpfile);
+ ib->dirty = FALSE;
+ return 0;
+ }
+
+lose:
+ unlink(tmpfile);
+ g_free(tmpfile);
+ return -1;
+}
+
+int
+ibex_close(ibex *ib)
+{
+ ibex_file *ibf;
+
+ if (ib->dirty && ibex_write(ib) == -1)
+ return -1;
+
+ g_tree_traverse(ib->files, free_file, G_IN_ORDER, NULL);
+ g_tree_destroy(ib->files);
+ g_hash_table_foreach(ib->words, free_word, NULL);
+ g_hash_table_destroy(ib->words);
+
+ while (ib->oldfiles->len)
+ {
+ ibf = g_ptr_array_remove_index(ib->oldfiles, 0);
+ g_free(ibf->name);
+ g_free(ibf);
+ }
+ g_ptr_array_free(ib->oldfiles, TRUE);
+ g_free(ib->path);
+ g_free(ib);
+
+ return 0;
+}
+
+static gint
+free_file(gpointer key, gpointer value, gpointer data)
+{
+ ibex_file *ibf = value;
+
+ g_free(ibf->name);
+ g_free(ibf);
+ return FALSE;
+}
+
+static void
+free_word(gpointer key, gpointer value, gpointer data)
+{
+ g_free(key);
+ g_ptr_array_free(value, TRUE);
+}
+
+static char *
+get_compressed_word(FILE *f, char **lastword)
+{
+ char *buf, *p;
+ int c, size;
+
+ c = getc(f);
+ if (c == EOF)
+ return NULL;
+
+ size = c + 10;
+ buf = g_malloc(size);
+ if (*lastword)
+ strncpy(buf, *lastword, c);
+ p = buf + c;
+ do
+ {
+ c = getc(f);
+ if (c == EOF)
+ return NULL;
+ if (p == buf + size)
+ {
+ buf = g_realloc(buf, size + 10);
+ p = buf + size;
+ size += 10;
+ }
+ *p++ = c;
+ }
+ while (c != 0);
+
+ *lastword = buf;
+ return buf;
+}
+
+static void
+write_number(FILE *f, unsigned long number)
+{
+ int i, flag = 0;
+ char buf[4];
+
+ i = 4;
+ do
+ {
+ buf[--i] = (number & 0x7F) | flag;
+ number = number >> 7;
+ flag = 0x80;
+ }
+ while (number != 0);
+
+ fwrite(buf + i, 1, 4 - i, f);
+}
+
+static unsigned long
+read_number(FILE *f)
+{
+ int byte;
+ unsigned long num;
+
+ num = 0;
+ do
+ {
+ byte = getc(f);
+ num = num << 7 | (byte & 0x7F);
+ }
+ while (byte & 0x80);
+
+ return num;
+}
+
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