Small change in database. Adding basic functions to convert hash to text and back
diff --git a/src/hash-string-converter.cc b/src/hash-string-converter.cc
new file mode 100644
index 0000000..1c9a656
--- /dev/null
+++ b/src/hash-string-converter.cc
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012 University of California, Los Angeles
+ *
+ * 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 program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ * Zhenkai Zhu <zhenkai@cs.ucla.edu>
+ */
+
+#include "hash-string-converter.h"
+
+#include <boost/assert.hpp>
+#include <boost/throw_exception.hpp>
+#include <boost/make_shared.hpp>
+#include <openssl/evp.h>
+
+typedef boost::error_info<struct tag_errmsg, std::string> errmsg_info_str;
+typedef boost::error_info<struct tag_errmsg, int> errmsg_info_int;
+
+#include <boost/archive/iterators/transform_width.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/archive/iterators/dataflow_exception.hpp>
+
+using namespace boost;
+using namespace boost::archive::iterators;
+using namespace std;
+
+
+template<class CharType>
+struct hex_from_4_bit
+{
+ typedef CharType result_type;
+ CharType operator () (CharType ch) const
+ {
+ const char *lookup_table = "0123456789abcdef";
+ // cout << "New character: " << (int) ch << " (" << (char) ch << ")" << "\n";
+ BOOST_ASSERT (ch < 16);
+ return lookup_table[static_cast<size_t>(ch)];
+ }
+};
+
+typedef transform_iterator<hex_from_4_bit<string::const_iterator::value_type>,
+ transform_width<string::const_iterator, 4, 8, string::const_iterator::value_type> > string_from_binary;
+
+
+template<class CharType>
+struct hex_to_4_bit
+{
+ typedef CharType result_type;
+ CharType operator () (CharType ch) const
+ {
+ const signed char lookup_table [] = {
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1,
+ -1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+ };
+
+ // cout << "New character: " << hex << (int) ch << " (" << (char) ch << ")" << "\n";
+ signed char value = -1;
+ if ((unsigned)ch < 128)
+ value = lookup_table [(unsigned)ch];
+ if (value == -1)
+ BOOST_THROW_EXCEPTION (Error::HashConversion () << errmsg_info_int ((int)ch));
+
+ return value;
+ }
+};
+
+typedef transform_width<transform_iterator<hex_to_4_bit<string::const_iterator::value_type>, string::const_iterator>, 8, 4> string_to_binary;
+
+
+std::ostream &
+operator << (std::ostream &os, const Hash &hash)
+{
+ if (hash.m_length == 0)
+ return os;
+
+ ostreambuf_iterator<char> out_it (os); // ostream iterator
+ // need to encode to base64
+ copy (string_from_binary (reinterpret_cast<const char*> (hash.m_buf)),
+ string_from_binary (reinterpret_cast<const char*> (hash.m_buf+hash.m_length)),
+ out_it);
+
+ return os;
+}
+
+Hash::Hash (const std::string &hashInTextEncoding)
+{
+ if (hashInTextEncoding.size () == 0)
+ {
+ m_buf = 0;
+ m_length = 0;
+ return;
+ }
+
+ if (hashInTextEncoding.size () > EVP_MAX_MD_SIZE * 2)
+ {
+ cerr << "Input hash is too long. Returning an empty hash" << endl;
+ m_buf = 0;
+ m_length = 0;
+ return;
+ }
+
+ unsigned char *m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+ unsigned char *end = copy (string_to_binary (hashInTextEncoding.begin ()),
+ string_to_binary (hashInTextEncoding.end ()),
+ m_buf);
+
+ m_length = end-m_buf;
+}
+
diff --git a/src/hash-string-converter.h b/src/hash-string-converter.h
new file mode 100644
index 0000000..1a84065
--- /dev/null
+++ b/src/hash-string-converter.h
@@ -0,0 +1,93 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012 University of California, Los Angeles
+ *
+ * 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 program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ * Zhenkai Zhu <zhenkai@cs.ucla.edu>
+ */
+
+#ifndef HASH_STRING_CONVERTER_H
+#define HASH_STRING_CONVERTER_H
+
+#include <string.h>
+#include <iostream>
+#include <boost/shared_ptr.hpp>
+#include <boost/exception/all.hpp>
+
+class Hash
+{
+public:
+ Hash (const void *buf, size_t length)
+ : m_length (length)
+ {
+ m_buf = new unsigned char [length];
+ memcpy (m_buf, buf, length);
+ }
+
+ Hash (const std::string &hashInTextEncoding);
+
+ ~Hash ()
+ {
+ delete [] m_buf;
+ }
+
+ bool
+ IsZero () const
+ {
+ return m_length == 0 ||
+ (m_length == 1 && m_buf[0] == 0);
+ }
+
+ bool
+ operator == (const Hash &otherHash) const
+ {
+ if (m_length != otherHash.m_length)
+ return false;
+
+ return memcmp (m_buf, otherHash.m_buf, m_length) == 0;
+ }
+
+ const void *
+ GetHash () const
+ {
+ return m_buf;
+ }
+
+ size_t
+ GetHashBytes () const
+ {
+ return m_length;
+ }
+
+private:
+ unsigned char *m_buf;
+ size_t m_length;
+
+ friend std::ostream &
+ operator << (std::ostream &os, const Hash &digest);
+};
+
+namespace Error {
+struct HashConversion : virtual boost::exception, virtual std::exception { };
+}
+
+typedef boost::shared_ptr<Hash> HashPtr;
+
+
+std::ostream &
+operator << (std::ostream &os, const Hash &digest);
+
+#endif // HASH_STRING_CONVERTER_H
diff --git a/src/sqlite-helper.cc b/src/sqlite-helper.cc
index c9c508b..7f3d829 100644
--- a/src/sqlite-helper.cc
+++ b/src/sqlite-helper.cc
@@ -21,6 +21,7 @@
#include "sqlite-helper.h"
// #include "sync-log.h"
+#include "hash-string-converter.h"
// Other options: VP_md2, EVP_md5, EVP_sha, EVP_sha1, EVP_sha256, EVP_dss, EVP_dss1, EVP_mdc2, EVP_ripemd160
#define HASH_FUNCTION EVP_sha256
@@ -44,23 +45,24 @@
CREATE INDEX SyncNodes_device_name ON SyncNodes (device_name); \
\
CREATE TABLE SyncLog( \
- state_hash BLOB NOT NULL PRIMARY KEY, \
+ state_id INTEGER PRIMARY KEY AUTOINCREMENT, \
+ state_hash BLOB NOT NULL UNIQUE, \
last_update TIMESTAMP NOT NULL \
); \
\
-CREATE TABLE \
- SyncStateNodes( \
- id INTEGER PRIMARY KEY AUTOINCREMENT, \
- state_hash BLOB NOT NULL \
- REFERENCES SyncLog (state_hash) ON UPDATE CASCADE ON DELETE CASCADE, \
+CREATE TABLE \
+ SyncStateNodes( \
+ id INTEGER PRIMARY KEY AUTOINCREMENT, \
+ state_id INTEGER NOT NULL \
+ REFERENCES SyncLog (state_id) ON UPDATE CASCADE ON DELETE CASCADE, \
device_id INTEGER NOT NULL \
REFERENCES SyncNodes (device_id) ON UPDATE CASCADE ON DELETE CASCADE, \
seq_no INTEGER NOT NULL \
); \
\
CREATE INDEX SyncStateNodes_device_id ON SyncStateNodes (device_id); \
-CREATE INDEX SyncStateNodes_state_hash ON SyncStateNodes (state_hash); \
-CREATE INDEX SyncStateNodes_seq_no ON SyncStateNodes (seq_no); \
+CREATE INDEX SyncStateNodes_state_id ON SyncStateNodes (state_id); \
+CREATE INDEX SyncStateNodes_seq_no ON SyncStateNodes (seq_no); \
\
CREATE TRIGGER SyncLogGuard_trigger \
BEFORE INSERT ON SyncLog \
@@ -96,14 +98,6 @@
char *errmsg = 0;
res = sqlite3_exec (m_db, INIT_DATABASE.c_str (), NULL, NULL, &errmsg);
- // if (res != SQLITE_OK && errmsg != 0)
- // {
- // std::cerr << "DEBUG: " << errmsg << std::endl;
- // sqlite3_free (errmsg);
- // }
-
- res = sqlite3_exec (m_db, "INSERT INTO SyncLog (state_hash, last_update) SELECT hash(device_name, seq_no), datetime('now') FROM SyncNodes ORDER BY device_name",
- NULL, NULL, &errmsg);
if (res != SQLITE_OK && errmsg != 0)
{
std::cerr << "DEBUG: " << errmsg << std::endl;
@@ -121,6 +115,34 @@
}
void
+DbHelper::rememberStateInStateLog ()
+{
+ char *errmsg = 0;
+ int res = sqlite3_exec (m_db, " \
+BEGIN TRANSACTION; \
+INSERT INTO SyncLog \
+ (state_hash, last_update) \
+ SELECT \
+ hash(device_name, seq_no), datetime('now') \
+ FROM SyncNodes \
+ ORDER BY device_name; \
+ \
+INSERT INTO SyncStateNodes \
+ (state_id, device_id, seq_no) \
+ SELECT last_insert_rowid(), device_id, seq_no \
+ FROM SyncNodes; \
+COMMIT; \
+",
+ NULL, NULL, &errmsg);
+ if (res != SQLITE_OK && errmsg != 0)
+ {
+ std::cerr << "DEBUG: " << errmsg << std::endl;
+ sqlite3_free (errmsg);
+ }
+}
+
+
+void
DbHelper::hash_xStep (sqlite3_context *context, int argc, sqlite3_value **argv)
{
if (argc != 2)
@@ -172,7 +194,8 @@
if (*hash_context == 0) // no rows
{
- sqlite3_result_null (context);
+ char charNullResult = 0;
+ sqlite3_result_blob (context, &charNullResult, 1, SQLITE_TRANSIENT); //SQLITE_TRANSIENT forces to make a copy
return;
}
@@ -187,3 +210,37 @@
EVP_MD_CTX_destroy (*hash_context);
}
+
+void
+DbHelper::hash2str_Func (sqlite3_context *context, int argc, sqlite3_value **argv)
+{
+ if (argc != 1 || sqlite3_value_type (argv[0]) != SQLITE_BLOB)
+ {
+ sqlite3_result_error (context, "Wrong arguments are supplied for ``hash2str'' function", -1);
+ return;
+ }
+
+ int hashBytes = sqlite3_value_bytes (argv[0]);
+ const void *hash = sqlite3_value_blob (argv[0]);
+
+ std::ostringstream os;
+ os << Hash (hash, hashBytes);
+ sqlite3_result_text (context, os.str ().c_str (), -1, SQLITE_TRANSIENT);
+}
+
+void
+DbHelper::str2hash_Func (sqlite3_context *context, int argc, sqlite3_value **argv)
+{
+ if (argc != 1 || sqlite3_value_type (argv[0]) != SQLITE_TEXT)
+ {
+ sqlite3_result_error (context, "Wrong arguments are supplied for ``str2hash'' function", -1);
+ return;
+ }
+
+ size_t hashTextBytes = sqlite3_value_bytes (argv[0]);
+ const unsigned char *hashText = sqlite3_value_text (argv[0]);
+
+ Hash hash (std::string (reinterpret_cast<const char*> (hashText), hashTextBytes));
+ sqlite3_result_blob (context, hash.GetHash (), hash.GetHashBytes (), SQLITE_TRANSIENT);
+}
+
diff --git a/src/sqlite-helper.h b/src/sqlite-helper.h
index 6874259..b710646 100644
--- a/src/sqlite-helper.h
+++ b/src/sqlite-helper.h
@@ -35,14 +35,33 @@
DbHelper (const std::string &path);
~DbHelper ();
-
-
+ void
+ updateDeviceSeqno ();
+
+ std::string
+ LookupForwardingAlias (const std::string &deviceName);
+
+ void
+ updateForwardingAlias ();
+
+ /**
+ * Create an entry in SyncLog and SyncStateNodes corresponding to the current state of SyncNodes
+ */
+ void
+ rememberStateInStateLog ();
+
private:
static void
- hash_xStep (sqlite3_context*,int,sqlite3_value**);
+ hash_xStep (sqlite3_context *context, int argc, sqlite3_value **argv);
static void
- hash_xFinal (sqlite3_context*);
+ hash_xFinal (sqlite3_context *context);
+
+ static void
+ hash2str_Func (sqlite3_context *context, int argc, sqlite3_value **argv);
+
+ static void
+ str2hash_Func (sqlite3_context *context, int argc, sqlite3_value **argv);
private:
sqlite3 *m_db;