BOOL
FileManager::seek(off_t offset)
{
if (!_compressed) {
_file->seek(offset);
_stream->avail_in = 0;
return TRUE;
}
/* if seek backwards, simply start from the beginning */
if (offset < _stream->total_out) {
_file->seek(0);
inflateEnd(_stream);
_reset(); /* this resets total_out to 0! */
inflateInit2(_stream, -15);
_stream->next_in = _inbuf;
_check_header(); /* skip the .gz header */
}
/* to seek forwards, throw away data */
if (offset > _stream->total_out) {
off_t toskip = offset - _stream->total_out;
size_t skipped = _skip_compressed(toskip);
if (skipped != toskip)
return FALSE;
}
return TRUE;
}
/**
* fast version of write the database
*
* @param d database handle
*/
void fast_writedb(struct db *d)
{
// when you create a new database,
// you don't know the size of it,
// so we can't write all stuffs once
// what we could make it fast is,
// not free the list, left it to OS
FILE *f = NULL;
if ((f = fopen(d->fname, "wb")) == NULL)
{
hooks.log("failed to open file %s!\n", d->fname);
return ;
}
// simple safety check
if(!d)
if ( _check_header(&(d->hdr)))
{
hooks.log("invalid databse!\n");
fclose(f);
return ;
}
// first write header
fwrite(&(d->hdr), sizeof(struct db_header), 1, f);
// write content
struct db_node *curr = d->head;
int i = 0;
int num = d->hdr.num;
for(; i < num; ++i)
{
if (curr == NULL ) break;
fwrite(curr->data, sizeof(char)*(d->hdr.len), 1, f);
curr = curr->next;
}
if (i != num)
{
hooks.log("unexpected error happens!\n");
}
fclose(f);
// no memory free here, leave it to OS
}
BOOL
FileManager::open(const TCHAR *name, uint32_t flags)
{
if (!_file->open(name, flags))
return FALSE;
_reset();
if (inflateInit2(_stream, -15) != Z_OK)
goto errout;
_stream->next_in = _inbuf;
_check_header(); // skip the .gz header
return TRUE;
errout:
_file->close();
return FALSE;
}
/**
* write data base into disk
*
* @param d database handle
*/
void writedb(struct db *d)
{
FILE *f = NULL;
if ((f = fopen(d->fname, "wb")) == NULL)
{
hooks.log("failed to open file %s!\n", d->fname);
return ;
}
// simple safety check
if(d)
if ( _check_header(&(d->hdr)))
{
hooks.log("invalid databse!\n");
fclose(f);
return ;
}
// first write header
fwrite(&(d->hdr), sizeof(struct db_header), 1, f);
// write content
struct db_node *curr = d->head;
int i = 0;
int num = d->hdr.num;
for(; i < num; ++i)
{
if (curr == NULL ) break;
fwrite(curr->data, sizeof(char)*(d->hdr.len), 1, f);
curr = curr->next;
}
if (i != num)
{
hooks.log("unexpected error happens!\n");
}
fclose(f);
_free_db(d);
}
/**
* fast version of open database
*
* @param fname
*
* @return
*/
struct db* fast_opendb(const char* fname)
{
// get the header
FILE *f;
struct db *d = NULL;
if ((f = fopen(fname, "r")) == NULL)
{
hooks.log("can not open file %s!\n", fname);
return NULL;
}
d = (struct db*)hooks.malloc(sizeof(struct db));
strncpy(d->fname, fname, DB_NAME_LEN-1);
d->head = NULL;
d->tail = NULL;
d->curr = NULL;
d->hdr.len = 0;
d->hdr.magic = 0;
d->hdr.num = 0;
d->hdr.reserved = 0;
// constuct database handle
if (0 ==
fread(&(d->hdr), sizeof(struct db_header), 1,
f))
{
hooks.log("invalid database file!\n");
hooks.free(d);
d = NULL;
}
if (d)
if ( _check_header(&(d->hdr)) )
{
hooks.log("invalid databse header!\n");
hooks.free(d);
d = NULL;
}
// because the len of every node is fixed, we could
// read all nodes' data once, and link them to a list
if (d)
{
int len_total = d->hdr.num * d->hdr.len;
// for all nodes
int node_total = d->hdr.num * sizeof(struct db_node);
void *nodes = hooks.malloc(node_total);
void *chunk = hooks.malloc(len_total);
if (chunk == NULL || nodes == NULL)
{
hooks.log("insufficient memory!\n");
hooks.exit(-1);
}
// read all data at once
fread(chunk, len_total, 1, f);
// constuct database linked list
int cnt = d->hdr.num;
int len = d->hdr.len;
// init every node
struct db_node *curr = (struct db_node*)nodes;
int i = 0;
for(; i < cnt-1; ++i)
{
curr->len = len;
curr->data = NULL;
curr->next = (curr + 1);
curr = curr->next;
}
d->head = (struct db_node*)nodes;
d->tail = curr;
curr->len = len;
curr->data = NULL;
curr->next = NULL;
d->curr = NULL;
curr = d->head;
void *data_head = chunk;
for(i = 0; i < cnt; ++i)
{
if (curr == NULL) break;
curr->data = data_head;
curr = curr->next;
data_head = (unsigned char*)data_head + len;
}
curr = NULL;
data_head = NULL;
}
return d;
}
/**
* open an exist database with its name
*
* @param fname name of database
*
* @return opened database handle
*/
struct db* opendb(const char *fname)
{
FILE *f;
struct db *d = NULL;
if ((f = fopen(fname, "r")) == NULL)
{
hooks.log("can not open file %s!\n", fname);
return NULL;
}
d = (struct db*)hooks.malloc(sizeof(struct db));
strncpy(d->fname, fname, DB_NAME_LEN-1);
d->head = NULL;
d->tail = NULL;
d->curr = NULL;
d->hdr.len = 0;
d->hdr.magic = 0;
d->hdr.num = 0;
d->hdr.reserved = 0;
// constuct database handle
if (0 ==
fread(&(d->hdr), sizeof(struct db_header), 1,
f))
{
hooks.log("invalid database file!\n");
hooks.free(d);
d = NULL;
}
if (d)
if ( _check_header(&(d->hdr)) )
{
hooks.log("invalid databse header!\n");
hooks.free(d);
d = NULL;
}
if (d)
{
// construct node list
int cnt = d->hdr.num;
while(!feof(f) && cnt > 0)
{
struct db_node *n = new_node(d->hdr.len);
fread(n->data, sizeof(char)*(d->hdr.len),
1, f);
dump(d, n);d->hdr.num--;
--cnt;
}
if (cnt != 0)
{
hooks.log("unexpected file end!\n");
hooks.free(d);
d = NULL;
}
}
fclose(f);
return d;
}
size_t
FileManager::_read(void *buf, size_t len)
{
// starting point for crc computation
uint8_t *start = reinterpret_cast<uint8_t *>(buf);
if (_z_err == Z_DATA_ERROR || _z_err == Z_ERRNO) {
return -1;
}
if (_z_err == Z_STREAM_END) {
return 0; // EOF
}
_stream->next_out = reinterpret_cast<uint8_t *>(buf);
_stream->avail_out = len;
int got;
while (_stream->avail_out != 0) {
if (!_compressed) {
// Copy first the lookahead bytes
uint32_t n = _stream->avail_in;
if (n > _stream->avail_out)
n = _stream->avail_out;
if (n > 0) {
memcpy(_stream->next_out, _stream->next_in, n);
_stream->next_out += n;
_stream->next_in += n;
_stream->avail_out -= n;
_stream->avail_in -= n;
}
if (_stream->avail_out > 0) {
got = _file->read(_stream->next_out,
_stream->avail_out);
if (got == -1) {
return(got);
}
_stream->avail_out -= got;
}
return(int)(len - _stream->avail_out);
}
if (_stream->avail_in == 0 && !_z_eof) {
got = _file->read(_inbuf, Z_BUFSIZE);
if (got <= 0)
_z_eof = 1;
_stream->avail_in = got;
_stream->next_in = _inbuf;
}
_z_err = inflate(_stream, Z_NO_FLUSH);
if (_z_err == Z_STREAM_END) {
/* Check CRC and original size */
_crc = crc32(_crc, start,(unsigned int)
(_stream->next_out - start));
start = _stream->next_out;
if (_get_long() != _crc ||
_get_long() != _stream->total_out) {
_z_err = Z_DATA_ERROR;
} else {
/* Check for concatenated .gz files: */
_check_header();
if (_z_err == Z_OK) {
inflateReset(_stream);
_crc = crc32(0L, Z_NULL, 0);
}
}
}
if (_z_err != Z_OK || _z_eof)
break;
}
_crc = crc32(_crc, start,(unsigned int)(_stream->next_out - start));
return(int)(len - _stream->avail_out);
}
