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231 lines
5.2 KiB

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "file.h"
#include "tree.h"
//TODO: refactor both hash and this hash table into a single one??
struct iso_file *
iso_file_new(struct iso_tree_node_file *f)
{
struct iso_file *file = calloc(1, sizeof(struct iso_file));
if (f->node.procedence == LIBISO_NEW) {
file->path = f->loc.path; /*TODO strdup? it needs to be free on clear then */
file->real_dev = f->node.attrib.st_dev;
file->real_ino = f->node.attrib.st_ino;
} else {
file->block = f->loc.block;
file->prev_img = 1;
file->real_dev = 0; /* we use 0 as dev for prev. session files */
/* don't take care about inode number read from RR TX, block
* number is good enouht for this. Moreover, when we are modifying
* an image, we will modify file->block with the block where the
* file needs to be written in the new image. So, we store the block
* in original image here, because we will need to use it for
* reading file contents */
file->real_ino = f->loc.block;
}
file->size = f->node.attrib.st_size;
file->nlink = 1;
file->sort_weight = f->sort_weight;
return file;
}
static unsigned int
iso_file_table_hash(const char *path)
{
unsigned int hash_num=0;
const char *c;
c=path;
while(*c)
hash_num = (hash_num << 15) + (hash_num << 3) + (hash_num >> 3) + *c++;
return hash_num % FILE_HASH_NODES;
}
static inline unsigned int
iso_file_table_hash_inode(dev_t dev, ino_t ino)
{
return (dev ^ ino) % FILE_HASH_NODES;
}
struct iso_file_table*
iso_file_table_new(int cache_inodes)
{
struct iso_file_table *table = calloc(1, sizeof(struct iso_file_table));
table->cache_inodes = cache_inodes;
return table;
}
static struct iso_file_hash_node *
iso_file_table_node_new(struct iso_file *file)
{
struct iso_file_hash_node *node;
node = calloc(1, sizeof(struct iso_file_hash_node) );
node->file = file;
return node;
}
static void
iso_file_table_node_free(struct iso_file_hash_node *node)
{
free(node->file);
free(node);
}
void
iso_file_table_clear(struct iso_file_table *ft)
{
int i;
for (i=0; i < FILE_HASH_NODES; i++) {
struct iso_file_hash_node *node;
node=ft->table[i];
if (!node)
continue;
ft->table[i] = NULL;
do {
struct iso_file_hash_node *next;
next = node->next;
iso_file_table_node_free(node);
node = next;
} while (node);
}
ft->count = 0;
}
/**
* return 0 if equal, != 0 if not
*/
static int
iso_table_compare_files(struct iso_file_table *ft,
struct iso_file *f1, struct iso_file *f2)
{
assert(ft && f1 && f2);
if (f1->prev_img || f2->prev_img) {
if (f1->prev_img && f2->prev_img)
return f1->real_ino != f2->real_ino;
else
return 1;
}
if (ft->cache_inodes) {
return (f1->real_dev != f2->real_dev) || (f1->real_ino != f2->real_ino);
} else {
return strcmp(f1->path, f2->path);
}
}
int
iso_file_table_add_file(struct iso_file_table *ft, struct iso_file *f)
{
struct iso_file_hash_node *node;
unsigned int hash_num;
assert(ft && f);
/* find the hash number */
if (f->prev_img)
hash_num = f->real_ino % FILE_HASH_NODES;
else if (ft->cache_inodes)
hash_num = iso_file_table_hash_inode(f->real_dev, f->real_ino);
else
hash_num = iso_file_table_hash(f->path);
/* insert it */
node = ft->table[hash_num];
/* unfortunately, we can't safely consider that a file
* won't be twice in the hash table so make sure it
* doesn't already exists */
if (!node) {
ft->table[hash_num]=iso_file_table_node_new(f);
ft->count++;
return 1;
}
/* if it's already in, we don't do anything */
if (!iso_table_compare_files(ft, f, node->file))
return 0;
while (node->next) {
node = node->next;
/* if it's already in, we don't do anything */
if (!iso_table_compare_files(ft, f, node->file))
return 0;
}
node->next = iso_file_table_node_new(f);
ft->count++;
return 1;
}
/** 0 on equal, != 0 otherwise */
static int
iso_table_compare_node_file(struct iso_file_table *ft,
struct iso_tree_node_file *f1, struct iso_file *f2)
{
assert(ft && f1 && f2);
if (f1->node.procedence || f2->prev_img) {
if (f1->node.procedence && f2->prev_img)
return f1->loc.block != f2->real_ino;
else
return 1;
}
if (ft->cache_inodes) {
return (f1->node.attrib.st_dev != f2->real_dev)
|| (f1->node.attrib.st_ino != f2->real_ino);
} else {
return strcmp(f1->loc.path, f2->path);
}
}
struct iso_file *
iso_file_table_lookup(struct iso_file_table *ft, struct iso_tree_node_file *f)
{
struct iso_file_hash_node *node;
unsigned int hash_num;
int equal;
assert(ft && f);
/* find the hash number */
if (f->node.procedence == LIBISO_PREVIMG)
hash_num = f->loc.block % FILE_HASH_NODES;
else if ( ft->cache_inodes )
hash_num = iso_file_table_hash_inode(f->node.attrib.st_dev,
f->node.attrib.st_ino);
else
hash_num = iso_file_table_hash(f->loc.path);
node = ft->table[hash_num];
if (!node)
return NULL;
equal = !iso_table_compare_node_file(ft, f, node->file);
if (equal)
return node->file;
while (node->next) {
node = node->next;
equal = !iso_table_compare_node_file(ft, f, node->file);
if (equal)
return node->file;
}
return NULL;
}