mirror of
https://github.com/Xahau/xahaud.git
synced 2025-12-06 17:27:52 +00:00
33c5f98824
This introduces changes in nudb to improve speed, reduce database size, and enhance correctness. The most significant change is to store hashes rather than entire keys in the key file. The output of the hash function is reduced to 48 bits, and stored directly in buckets. The API is also modified to introduce a Codec parameter allowing for compression and decompression to be supported in the implementation itself rather than callers. THe data file no longer contains a salt, as the salt is applicable only to the key and log files. This allows a data file to have multiple key files with different salt values. To distinguish physical files belonging to the same logical database, a new field UID is introduced. The UID is a 64-bit random value generated once on creation and stored in all three files. Buckets are zero filled to the end of each block, this is a security measure to prevent unintended contents of memory getting stored to disk. NuDB offers the varint integer type, this is identical to the varint described by Google. * Add varint * Add Codec template argument * Add "api" convenience traits * Store hash in buckets * istream can throw short read errors * Support std::uint8_t format in streams * Make file classes part of the public interface * Remove buffers pessimization, replace with buffer * Consolidate creation utility functions to the same header * Zero fill unused areas of buckets on disk * More coverage and improvements to the recover test * Fix file read/write to loop until all bytes processed * Add verify_fast, faster verify for large databases The database version number is incremented to 2; older databases can no longer be opened and should be deleted.
124 lines
3.0 KiB
C++
124 lines
3.0 KiB
C++
//------------------------------------------------------------------------------
|
|
/*
|
|
This file is part of Beast: https://github.com/vinniefalco/Beast
|
|
Copyright 2014, Vinnie Falco <vinnie.falco@gmail.com>
|
|
|
|
Permission to use, copy, modify, and/or distribute this software for any
|
|
purpose with or without fee is hereby granted, provided that the above
|
|
copyright notice and this permission notice appear in all copies.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
//==============================================================================
|
|
|
|
#ifndef BEAST_NUDB_COMMON_H_INCLUDED
|
|
#define BEAST_NUDB_COMMON_H_INCLUDED
|
|
|
|
#include <stdexcept>
|
|
#include <string>
|
|
|
|
namespace beast {
|
|
namespace nudb {
|
|
|
|
// Commonly used types
|
|
|
|
enum class file_mode
|
|
{
|
|
scan, // read sequential
|
|
read, // read random
|
|
append, // read random, write append
|
|
write // read random, write random
|
|
};
|
|
|
|
using path_type = std::string;
|
|
|
|
// All exceptions thrown by nudb are derived
|
|
// from std::runtime_error except for fail_error
|
|
|
|
/** Thrown when a codec fails, e.g. corrupt data. */
|
|
struct codec_error : std::runtime_error
|
|
{
|
|
template <class String>
|
|
explicit
|
|
codec_error (String const& s)
|
|
: runtime_error(s)
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Base class for all errors thrown by file classes. */
|
|
struct file_error : std::runtime_error
|
|
{
|
|
template <class String>
|
|
explicit
|
|
file_error (String const& s)
|
|
: runtime_error(s)
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Thrown when file bytes read are less than requested. */
|
|
struct file_short_read_error : file_error
|
|
{
|
|
file_short_read_error()
|
|
: file_error (
|
|
"nudb: short read")
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Thrown when file bytes written are less than requested. */
|
|
struct file_short_write_error : file_error
|
|
{
|
|
file_short_write_error()
|
|
: file_error (
|
|
"nudb: short write")
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Thrown when end of istream reached while reading. */
|
|
struct short_read_error : std::runtime_error
|
|
{
|
|
short_read_error()
|
|
: std::runtime_error(
|
|
"nudb: short read")
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Base class for all exceptions thrown by store. */
|
|
class store_error : public std::runtime_error
|
|
{
|
|
public:
|
|
template <class String>
|
|
explicit
|
|
store_error (String const& s)
|
|
: runtime_error(s)
|
|
{
|
|
}
|
|
};
|
|
|
|
/** Thrown when corruption in a file is detected. */
|
|
class store_corrupt_error : public store_error
|
|
{
|
|
public:
|
|
template <class String>
|
|
explicit
|
|
store_corrupt_error (String const& s)
|
|
: store_error(s)
|
|
{
|
|
}
|
|
};
|
|
|
|
} // nudb
|
|
} // beast
|
|
|
|
#endif
|