/*
** Copyright (c) 2006 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License version 2 as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** General Public License for more details.
**
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA 02111-1307, USA.
**
** Author contact information:
** drh@hwaci.com
** http://www.hwaci.com/drh/
**
*******************************************************************************
**
** Procedures store and retrieve records from the repository
*/
#include "config.h"
#include "content.h"
#include <assert.h>
/*
** Return the srcid associated with rid. Or return 0 if rid is
** original content and not a delta.
*/
static int findSrcid(int rid, const char *zDb){
Stmt qsrc;
int srcid;
if( zDb ){
db_prepare(&qsrc, "SELECT srcid FROM %s.delta WHERE rid=%d", zDb, rid);
}else{
db_prepare(&qsrc, "SELECT srcid FROM delta WHERE rid=%d", rid);
}
if( db_step(&qsrc)==SQLITE_ROW ){
srcid = db_column_int(&qsrc, 0);
}else{
srcid = 0;
}
db_finalize(&qsrc);
return srcid;
}
/*
** Extract the content for ID rid and put it into the
** uninitialized blob.
*/
void content_get_from_db(int rid, Blob *pBlob, const char *zDb){
Stmt q;
int srcid;
assert( g.repositoryOpen );
srcid = findSrcid(rid, zDb);
if( zDb ){
db_prepare(&q,
"SELECT content FROM %s.blob WHERE rid=%d AND size>=0",
zDb, rid
);
}else{
db_prepare(&q,
"SELECT content FROM blob WHERE rid=%d AND size>=0",
rid
);
}
if( srcid ){
Blob src;
content_get_from_db(srcid, &src, zDb);
if( db_step(&q)==SQLITE_ROW ){
Blob delta;
db_ephemeral_blob(&q, 0, &delta);
blob_uncompress(&delta, &delta);
blob_init(pBlob,0,0);
blob_delta_apply(&src, &delta, pBlob);
blob_reset(&delta);
}else{
blob_init(pBlob, 0, 0);
}
blob_reset(&src);
}else{
if( db_step(&q)==SQLITE_ROW ){
db_ephemeral_blob(&q, 0, pBlob);
blob_uncompress(pBlob, pBlob);
}else{
blob_init(pBlob,0, 0);
}
}
db_finalize(&q);
}
void content_get(int rid, Blob *pBlob){
content_get_from_db(rid, pBlob, 0);
}
/*
** COMMAND: test-content-get
**
** Extract a blob from the database and write it into a file.
*/
void test_content_get_cmd(void){
int rid;
Blob content;
const char *zFile;
if( g.argc!=4 && g.argc!=3 ) usage("RECORDID ?FILENAME?");
zFile = g.argc==4 ? g.argv[3] : "-";
db_must_be_within_tree();
rid = name_to_rid(g.argv[2]);
content_get(rid, &content);
blob_write_to_file(&content, zFile);
}
/*
** COMMAND: test-content-rawget
**
** Extract a blob from the database and write it into a file. This
** version does not expand the delta.
*/
void test_content_rawget_cmd(void){
int rid;
Blob content;
const char *zFile;
if( g.argc!=4 && g.argc!=3 ) usage("RECORDID ?FILENAME?");
zFile = g.argc==4 ? g.argv[3] : "-";
db_must_be_within_tree();
rid = name_to_rid(g.argv[2]);
blob_zero(&content);
db_blob(&content, "SELECT content FROM blob WHERE rid=%d", rid);
blob_uncompress(&content, &content);
blob_write_to_file(&content, zFile);
}
/*
** Write content into the database. Return the record ID. If the
** content is already in the database, just return the record ID.
**
** A phantom is written if pBlob==0. If pBlob==0 then the UUID is set
** to zUuid. Otherwise zUuid is ignored.
**
** If the record already exists but is a phantom, the pBlob content
** is inserted and the phatom becomes a real record.
*/
int content_put(Blob *pBlob, const char *zUuid){
int size;
int rid;
Stmt s1;
Blob cmpr;
Blob hash;
assert( g.repositoryOpen );
if( pBlob==0 ){
blob_init(&hash, zUuid, -1);
size = -1;
}else{
sha1sum_blob(pBlob, &hash);
size = blob_size(pBlob);
}
db_begin_transaction();
/* Check to see if the entry already exists and if it does whether
** or not the entry is a phantom
*/
db_prepare(&s1, "SELECT rid, size FROM blob WHERE uuid=%B", &hash);
if( db_step(&s1)==SQLITE_ROW ){
rid = db_column_int(&s1, 0);
if( db_column_int(&s1, 1)>=0 || pBlob==0 ){
/* Either the entry is not a phantom or it is a phantom but we
** have no data with which to dephathomize it. In either case,
** there is nothing for use to do other than return the RID. */
db_finalize(&s1);
db_end_transaction(0);
return rid;
}
}else{
rid = 0; /* No entry with the same UUID currently exists */
}
db_finalize(&s1);
/* Construct a received-from ID if we do not already have one */
if( g.rcvid==0 && pBlob!=0 ){
db_multi_exec(
"INSERT INTO rcvfrom(uid, mtime, nonce, ipaddr)"
"VALUES(%d, julianday('now'), %Q, %Q)",
g.userUid, g.zNonce, g.zIpAddr
);
g.rcvid = db_last_insert_rowid();
}
if( rid>0 ){
/* We are just adding data to a phantom */
assert( pBlob!=0 );
db_prepare(&s1,
"UPDATE blob SET rcvid=%d, size=%d, content=:data WHERE rid=%d",
g.rcvid, size, rid
);
blob_compress(pBlob, &cmpr);
db_bind_blob(&s1, ":data", &cmpr);
db_exec(&s1);
}else{
/* We are creating a new entry */
db_prepare(&s1,
"INSERT INTO blob(rcvid,size,uuid,content)"
"VALUES(%d,%d,'%s',:data)",
g.rcvid, size, blob_str(&hash)
);
if( pBlob ){
blob_compress(pBlob, &cmpr);
db_bind_blob(&s1, ":data", &cmpr);
}
db_exec(&s1);
rid = db_last_insert_rowid();
}
/* Finish the transaction and cleanup */
db_finalize(&s1);
db_end_transaction(0);
blob_reset(&hash);
/* Make arrangements to verify that the data can be recovered
** before we commit */
if( pBlob ){
blob_reset(&cmpr);
verify_before_commit(rid);
}
return rid;
}
/*
** COMMAND: test-content-put
**
** Extract a blob from the database and write it into a file.
*/
void test_content_put_cmd(void){
int rid;
Blob content;
if( g.argc!=3 ) usage("FILENAME");
db_must_be_within_tree();
user_select();
blob_read_from_file(&content, g.argv[2]);
rid = content_put(&content, 0);
printf("inserted as record %d\n", rid);
}
/*
** Make sure the content at rid is the original content and is not a
** delta.
*/
void content_undelta(int rid){
if( findSrcid(rid, 0)>0 ){
Blob x;
Stmt s;
content_get(rid, &x);
db_prepare(&s, "UPDATE blob SET content=:c WHERE rid=%d", rid);
db_bind_blob(&s, ":c", &x);
db_exec(&s);
db_finalize(&s);
db_multi_exec("DELETE FROM delta WHERE rid=%d", rid);
}
}
/*
** COMMAND: test-content-undelta
**
** Make sure the content at RECORDID is not a delta
*/
void test_content_undelta_cmd(void){
int rid;
if( g.argc!=2 ) usage("RECORDID");
db_must_be_within_tree();
rid = atoi(g.argv[2]);
content_undelta(rid);
}
/*
** Change the storage of rid so that it is a delta of srcid.
**
** If rid is already a delta from some other place then no
** conversion occurs and this is a no-op unless force==1.
**
** If srcid is a delta that depends on rid, then srcid is
** converted to undeltaed text.
*/
void content_deltify(int rid, int srcid, int force){
int s;
Blob data, src, delta;
static Stmt s1, s2;
if( srcid==rid ) return;
if( !force && findSrcid(rid, 0)>0 ) return;
s = srcid;
while( (s = findSrcid(s, 0))>0 ){
if( s==rid ){
content_undelta(srcid);
break;
}
}
content_get(srcid, &src);
content_get(rid, &data);
blob_delta_create(&src, &data, &delta);
if( blob_size(&src)>=50 && blob_size(&data)>=50 &&
blob_size(&delta) < blob_size(&data)*0.75 ){
blob_compress(&delta, &delta);
db_static_prepare(&s1, "UPDATE blob SET content=:data WHERE rid=:rid");
db_static_prepare(&s2, "REPLACE INTO delta(rid,srcid)VALUES(:rid,:sid)");
db_bind_int(&s1, ":rid", rid);
db_bind_blob(&s1, ":data", &delta);
db_bind_int(&s2, ":rid", rid);
db_bind_int(&s2, ":sid", srcid);
db_begin_transaction();
db_exec(&s1);
db_exec(&s2);
db_end_transaction(0);
}
blob_reset(&src);
blob_reset(&data);
blob_reset(&delta);
verify_before_commit(rid);
}
/*
** COMMAND: test-content-deltify
**
** Convert the content at RID into a delta from SRCID.
*/
void test_content_deltify_cmd(void){
if( g.argc!=5 ) usage("RID SRCID FORCE");
db_must_be_within_tree();
content_deltify(atoi(g.argv[2]), atoi(g.argv[3]), atoi(g.argv[4]));
}