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Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..32e74ff --- /dev/null +++ b/ChangeLog @@ -0,0 +1,590 @@ +17 September 2011
+ Itzam/C 6.0.4
+
+ * Added "overwrite" function for datafiles, to allow partial modification
+ of existing records.
+
+28 July 2011
+ Itzam/C 6.0.3
+
+ * Changed itzam_btree_find such that if the returned_key pointer is NULL,
+ it does not copy the returned key. This slightly speeds up searches where
+ you only need to check for key existence, and not consistency.
+
+ * Major rewrite of itzam_btree_test_threads.c for Unix / Linux systems.
+ It now compares single versus multi thread performance.
+
+ * Fixed a bug in setting flag in file-level unlock.
+
+ * Renamed datafile lock flag to avoid confusion.
+
+ * Fixed a few typos (typoes?) in comments. I'm sure there are more. :)
+
+ * Fixed ugliness in the documentation headings.
+
+ * Fixed warnings from test programs about printf formats.
+
+ * Itzam/C should NOT be compiled with GCC's -ftree-vectorize flag; it will
+ SEGFAULT when run. Recommended CFLAGS for compiling on a GNU/Linux system are:
+
+ -std=gnu99 -O3 -Wall -pedantic -fno-tree-vectorize -g0 -march=native
+
+7 July 2011
+ Itzam/C 6.0.2
+
+ * Fixed libpthread link problem on some systems
+
+6 July 2011
+ Itzam/C 6.0.1
+
+ * Fixed stupid error in configure.ac that prevented .so files from being generated
+ on some systems.
+
+ * Fixed pointer cast warning in itzam_btree_test_strvar.c
+
+1 June 2011
+ Itzam/C 6.0.0
+
+ <<<<----------------- IMPORTANT NOTICE -------------------->>>>
+ Compatability warning: Data files created with previous versions
+ are not compatible with version 6.0 due to changes in struct
+ packing. You can change the pack() pragma in itzam.h to retsore
+ compatability with older files.
+ <<<<----------------- IMPORTANT NOTICE -------------------->>>>
+
+ * Massive code cleanup and cruft removal. After 20 years, the
+ codebase had gotten kind of cranky, and it's been refurbished with
+ great vigor.
+
+ * Simplified OS detection. Itzam now recognizes two operating systems,
+ Windows and POSIX, both in 32- and 64-bit modes. Linxu is, of
+ course, a POSIX system.
+
+ * Incorporated a number of features that were built into proprietary
+ variations of Itzam.
+
+ * Exhaustive testing in multiprocessing environments, with dozens of
+ threads and several processes accessing an Itzam database
+ simultaneously. This codebase is the core of mission critical apps
+ running 24/7/265 reliably. Coordination is implemented via shared
+ OS mutexes.
+
+ * This code is 4 to 5 times faster than any previous version of Itzam,
+ largely due to the use of shared memory for holding frequently
+ accessed information.
+
+ * Removed the hash table and matrix index types.
+
+ * All new test suite.
+
+ * All new projects (Windows Visual Studio 10.0) and autotools scripts
+ (Unix)
+
+ * Brand new, complete documentation, neatly formatted in PDF and HTML.
+
+ * The default error handler can now be assigned.
+
+5 April 2011
+ Itzam/C 5.1.0
+
+ * Added cross-platform mutexes for controlling multithreaded access
+ to datafiles and indexes. Within a single thread group, the mutexes
+ automatically avoid collisions between threads using Itzam fucntions
+ and structures. File locking (which already existed) should be used
+ when running separate executable images.
+
+ Mutexes are implemented for Windows and POSIX pthreads (works fine
+ on modern Linux and libc).
+
+ * Added additional error responses in many functions.
+
+ * Fixed an egregiously stupid problem involving chickens and eggs,
+ wherein I tried to cook an egg laid by a NULL chicken, to announce
+ the non-existence of the chicken that could not have laid the egg.
+
+ * Replaced lost file format version check.
+
+ * Made itzam_datafile_get_next_open a static (i.e., private) function.
+
+ * Fixed sychronization bug in field headers between threads.
+
+1 April 2010
+ Itzam/C 5.0.0
+
+ * <<----------------- IMPORTANT NOTICE ----------------->>>>
+ Version 5.0 of Itzam/Core is *not* source-code compatible with
+ previous versions.
+
+ If you have data stores based on a previous Itzam release, continue to
+ use that release. If you have questions about a conversion, please
+ contact Itzam's author at scott.ladd@coyotegulch.com.
+ <<----------------- IMPORTANT NOTICE ----------------->>>>
+
+ * Expanded, fully-commented tutorial program (see /tutorial directory)
+
+ * Itzam/Code is now renamed Itzam/C, or simply Itzam. This is the
+ reference implementation of the engine.
+
+ * Moved debug code to tools package
+
+ * 100% tested and verified on 32- and 64-bit Windows and Linux
+
+ * Modern 32- and 64-bit Windows DLL projects for Visual Studio 2008
+
+ * Revamped architecture of testing modules
+
+ * Removed all strings from Itzam/C; completely character set
+ neutral (tested with ASCII-8 and Unicode builds)
+
+ * Added infrstructure to support embedded XML shemea for future
+ Itzam/Designer product
+
+ * Optimizations throughout (nothing dramatic)
+
+ * Reduce library footprint.
+
+18 November 2009
+ Itzam/Core 4.0.8
+
+ * Updated for GPL 3
+
+ * Minor bug fixes, documentation updates, and clarifications
+
+17 June 2008
+ Itzam/Core 4.0.0
+
+ * <<----------------- IMPORTANT NOTICE ----------------->>>>
+ Version 4.0 of Itzam/Core is *not* compatible with any previous version.
+ If you have data stores based on a previous Itzam release, continue to
+ use that release. If you have questions about a conversion, please
+ contact Itzam's author at scott.ladd@coyotegulch.com.
+
+ * CHANGE: The basic structure of an Itzam file now stores an array of
+ fixed-length keys values for both B-tree and hash indexes.
+ This change reduced the number of intrinsic I/O operations
+ by eliminating the need to indirectly reference separately-stored
+ keys and records. This change also simplified many function
+ signatures.
+
+ What does this change mean? Essentially, each "key" is a fixed-length
+ value that can contain anything -- including references to records
+ stored anywhere. See the tutorial for examples of how this works.
+
+ * CHANGE: B-tree databases no longer support the "optimize" functions, as
+ these are no longer necessary due to the revised architecture.
+
+19 October 2006
+ Itzam/Core 3.1.1
+
+ CHANGE: Random number generator seed now uses /dev/random when possible
+ instead of time.
+
+ FIXED: Changed order of page writes in key redistribution.
+
+ FIXED: Removed unnecessary copying of links in removal.
+
+ FIXED: Minor indentation issues.
+
+24 September 2006
+ Itzam/Core 3.1.0
+
+ * CHANGE: As per requests from customers, Itzam now compiles as 100%
+ Standard ANSI/ISO C, without any POSIX headers or functions.
+
+ Using the GNU toolchain and building with GCC, the additional
+ configuration options are:
+
+ --enable-stdc
+ cause compilation with the "-std=c99 -DSTDC -DSTDCIO"
+
+ --enable-stdc89
+ cause compilation with "-std=c89 -DSTDC89 -DSTDCIO"
+
+ --enable-stdio
+ cause compilation with "-DSTDCIO"
+
+ By default, the configure script will generate Makefiles that
+ compile Itzam with with --std=gnu99.
+
+ All compiles use "-pedantic -Wall". POSIX I/O is used by default
+ unless one of the Standard C symbols above is defined.
+
+ On Microsoft C++, you will need to define the symbols in the project
+ settings if you do not want to compile for Visual C++'s default
+ flavor of C.
+
+ * CHANGE: Removed static data from the library, for better compatability
+ with some embedded platforms.
+
+ * CHANGE: Removed the itzam_comparator_string_ignore_case function,
+ since ANSI C offers no built-in way of performing a case-
+ insenstive strong comparison.
+
+ FIXED: Various annoying bugs in files like README.
+
+14 September 2006
+ Itzam/Core 3.0.1
+
+ * CHANGE: Can be compiled with either POSIX or Standard C I/O. If
+ STDC_IO is defined at compile time, Itzam uses Standard
+ C I/O (fopen, fwrite, etc); otherwise, it uses POSIX I/O
+ (open, write, etc.). This can be easily customized for
+ other I/O libraries; see the macro definitions in itzam.h.
+
+ For GNU toolchain builds, the ./configure option --enable-stdcio
+ generates makefiles that include -DSTDC_IO. Without that option,
+ the library is generated for POSIX I/O.
+
+ * FIXED Removed duplicate "rollback" in datafile open.
+
+ CHANGE: The usual comment and code clean-ups.
+
+27 August 2006
+ Itzam/Core 3.0.0
+
+ * NEW: Atomic file operations (transactions with commit/rollback).
+
+ * NEW: Hash-based indexes
+
+ * NEW: Memory allocation and release functions to generate Itzam
+ data structures.
+
+ CHANGE: Default compile now uses -pedantic -Wall switches to help
+ maintain code quality.
+
+ CHANGE: Minor improvements and clean-ups in test programs
+
+ CHANGE: Comment and code clean-up
+
+
+20 July 2006
+ Itzam/Core 2.8.2
+
+ FIXED: Bug that caused file sizes to increase under some
+ circumstances
+
+ FIXED: Bug in btree analysis that reported the wrong number
+ of pages
+
+ FIXED: Minor inefficiencies in deleted record list.
+
+28 February 2006
+ Itzam/Core 2.8.1 release
+
+ FIXED: Clean-up freeing of deleted list in itzam_data_close.
+
+ FIXED: Uninitialized deleted list pointer.
+
+21 February 2006
+ Itzam/Core 2.8.0 release
+
+ * FIXED: Bug in maintaining correct deleted record list across
+ multiple processes.
+
+ * CHANGE: ITZAM_UNKNOWN renamed to ITZAM_FAILED
+
+ ADDED: Functions to create index structures inside an existing
+ datafile; this allows multiple indexes to reside within a
+ single datafile. This affects the B-tree and matrix indexes.
+
+ CHANGE: Minor code clean-ups
+
+12 January 2006
+ Itzam/Core 2.7.1 release
+
+ FIXED: Windows only: Benign memory corruption bug caused by
+ difference in sizeof(bool) between C and C++.
+
+03 January 2006
+ Itzam/Core 2.7.0 release
+
+ * ADDED: Predefined key comparators for integers (signed and unsigned,
+ * 32- and 64-bit) and strings (case sensitive and insensistive).
+
+ * ADDED: Function to optimize a B-tree. Calling itzam_btree_optimize
+ * creates a new B-tree with identical contents to the
+ * original, but without any wasted space from deleted records.
+ * This can be particularly beneficial if a large number of
+ * records have been deleted, or if recently-added records are
+ * too large for placement in slots created by prior deletions.
+ *
+ * The optimized file can not overwrite the original B-tree
+ * file. You can always delete the old file when the new one
+ * is tested as acceptable. Itzam deliberately avoids replacing
+ * old data automatically as a safety measure.
+
+ * CHANGE: Each index now has a schema reference. A database schema
+ * will define relationships within a collection of table
+ * schemas. This is in preparation for a future version of
+ * Itzam that will support reflection and XML-based tools.
+
+ * CHANGE: Changed ITZAM_LOCK_* and itzam_lock_* to ITZAM_FILE_LOCK_*
+ * and itzam_file_lock_* to avoid confusion with thread locks.
+
+ CHANGE: Search functions are now iterative instead of recursive,
+ resulting in a performance boost.
+
+ CHANGE: Refined datafile reading.
+
+ CHANGE: Divided utility programs into tests and tools.
+
+ CHANGE: The Visual Studio projects have been completely revised and
+ expanded for both VS2003 and VS2005.
+
+ NOTE: When compiled with GCC, the code appears to perform
+ fastest if compiled with -fstrict-aliasing.
+
+ FIXED: Tiny memory leak in creating B-tree iterators. I don't
+ know why Valgrind didn't find this before!
+
+ FIXED: Overflow bug in "fillkill" test in itzam_btree_test.
+
+ FIXED: Minor code and comment cleanup
+
+23 December 2005
+ Itzam/Core 2.6.0 release
+
+ * ADDED: File locking via several user-selected mechanisms.
+ * Itzam is now usable in a multi-user, multi-processor
+ * application.
+ *
+ * The type of locking is specified upon file creation
+ * or opening, and may use operating system functions
+ * (fcntl/fsync on Linux, _locking/_commit on WindowsXP) or
+ * a secondary "lock file". In general, use ITZAM_FILE_LOCK_OS,
+ * as it ties file access directly to the operating system.
+ *
+ * PLEASE NOTE: File locking has been checked with as many
+ * as 16 processes hitting a single database file with mixed
+ * reads, writes, and removes; tests were performed on both
+ * Linux 2.6.24 and WindowsXP SP2. HOWEVER, file locking is
+ * highly dependent on device drivers and hardware
+ * configuration.
+
+ * CHANGE: Replace Standard C buffered I/O with low-level UNIX-style
+ * I/O (open, read, write, close). This is faster and works
+ * better with file locking, but is somewhat less universal
+ * due to silliness like Microsoft's addition of underscores
+ * (open is _open in Visual C++, for example).
+
+ * UPDATE: The doc/api_ref.txt file has been updated to reflect all
+ * of the recent changes.
+
+ * ADDED: Data file headers now contain a "schema" reference.
+ * This is not used in the current version of Itzam, but
+ * will be used in the future when XML schemas are
+ * implemented.
+
+ * ADDED: Record headers now contain a signature, to be used
+ * in future data recovery and analysis programs.
+
+ * CHANGE: Records are now tagged with a type, i.e. "B-tree page"
+ * to facilitate future plans for data recovery tools.
+ * These flags can be seen by running the itzam_data_dump
+ * program on any Itzam file.
+
+ CHANGE: Massive changes to the main test program, itzam_btree_test.
+ These include a restructuring of the program, the ability
+ to begin testing from an existing file, and implementation
+ of optional multiple processes and threads.
+
+ CHANGE: Modified output file names for itzam_btree_test and
+ itzam_matrix_test.
+
+ CHANGE: Began adding 2006 copyright dates as file are modified.
+
+ FIXED: Added checks to datafile functions so it doesn't try to
+ read/write/whatever on a file that isn't open.
+
+10 December 2005
+ Itzam/Core 2.5.0 release
+
+ * CHANGE: By default, the library is compiled for 32- or 64-bits
+ * based on the definition of these C preprocessor macros:
+ *
+ * ITZAM32 - forces 32-bit file pointers
+ *
+ * ITZAM64 - forces 64-bit file pointers
+ *
+ * JAVACOMPAT - forces 64-bit file pointers
+ *
+ * If none of the above are explicitly defined, Itzam defaults
+ * to 32-bit pointers, unless one of the following vendor
+ * symbols is defined by the compiler:
+ *
+ * GNU GCC: __LP64__
+ *
+ * Intel C++ for Linux: __LP64__, __IA64__
+ *
+ * Microsoft Visual C++: _M_X64, _M_IA64, _WIN64
+
+ ADDED: New is_open functions for datafiles and btrees
+
+ ADDED: itzam_btree_dump program
+
+ ADDED: ITZAM_ERROR_READ_DELETED error when reading a deleted
+ record.
+
+ CLEAN: Removed unused PAGE_ORDER from itzam_btree.cpp
+
+ CLEAN: Removed unused "skip" function
+
+ CLEAN: Removed redundant rewrite function
+
+ CLEAN: Removed B-tree page cache structures from itzam.h
+
+ CLEAN: Removed unused "max ref" code from B-trees
+
+ CLEAN: Minor comment fixes.
+
+ 1 December 2005
+ Itzam/Core 2.4.2 release
+
+ FIXED: Small memory leak in rare instance of btree key promotion
+
+ FIXED: Removed unused declaration from itzam.h
+
+30 November 2005
+ Itzam/Core 2.4.1 release
+
+ FIXED: Failure to initialize "max ref" component of btree header
+
+ CLEAN: Removed extraneous definitions from itzam.h
+
+29 November 2005
+ Itzam/Core 2.4.0 release
+
+ IMPORTANT: Itzam now defaults to 32-bit file address; the
+ preprocessor macro ITZAM64 must be defined during
+ compilation to generate an Itzam library with 64-bit
+ addressing. Previous versions of Itzam defaulted to 64-bit
+ file addressing.
+
+ Fixed trivial warnings in various source files
+
+ Removed unused code from several modules
+
+ Renamed and reorganized test programs
+
+ Fixed Visual C++ code generation problem when removing records
+
+23 November 2005
+ Itzam/Core 2.3.1 release
+
+ Fixed bug in reopening empty file
+
+21 November 2005
+ Itzam/Core 2.3.0 release
+
+ Added "order" argument to itzam_btree_open, with associated constants
+
+ Removed in-memory page cache, which was *slower* than direct
+ page reads
+
+ Optimized B-tree search routine
+
+ Tested with over 4 billion record operations
+
+15 November 2005
+ Itzam/Core 2.2.0 release
+
+ New "matrix" index type
+
+ Fixed memory memory subtle leaks
+
+ Faster Btree lookups
+
+10 November 2005
+ Itzam/Core 2.1.1 released
+
+ Fixed bug in management of deleted list
+
+ Added check for 64-bit datafile on 32-bit platforms
+
+8 November 2005
+ Itzam/Core 2.1.0 released
+
+ Entirely new scheme for handling deleted records. Instead of a linked
+ list, Itzam now uses a table. The table is *only* created if deletion
+ occurs on a given datafile.
+
+ Changed itzam_record_header.m_status to itzam_record_header.m_flags, from
+ an 8-bit value to a 32-bit bitmask.
+
+ Minor change to output of itzam_exercise
+
+ Simplified main loop of itzam_exercise
+
+ Fixed bugs in itzam_btree_insert_rec that resulted in excessively large files
+
+ Extended Itzam error condition to reflect improved error trapping
+
+ Improved error trapping in itzam_btree_remove
+
+ Fixed a few inconsistencies in using itzam_ref and itzam_int
+
+ Added new tests and datafile analyses
+
+ Fixed bug in itzam_datafile_rewind where it strated in the wrong place (duh)
+
+1 November 2005
+ Itzam/Core 2.0.0 released.
+
+ Compile-time support for generating version using 32-bit
+ file pointers (default is 64-bit pointers) by defining the
+ ITZAM32 symbol.
+
+ Embedded datafile version now includes number of bits in
+ a file reference.
+
+ Added functions to retrieve bits-per-reference and version.
+
+ Added Microsoft Visual Studio 2005 solution and project
+ files.
+
+ Changed fopen and sprintf function calls to reflect
+ Microsoft's obsession with "safety" in Visual C++ 14.0.
+
+ Fixed minor bug in itzam_datafile_rewrite.
+
+ Implemented a few minor "need better error handling" todos.
+
+ Minor optimizations and code clean-ups.
+
+ Minor changes to support C++ wrapper.
+
+9 October 2005
+ Itzam 1.2.0 released.
+
+ Added tutorial and API documentation.
+
+ Added Microsoft Visual Studio.NET 2003 solution and
+ projects.
+
+ Modified stress_btree.c for MS Visual C++.
+
+ Minor cruft removal.
+
+ Added tree structure analysis routines to debug facilities
+ and stress_btree test program.
+
+5 May 2005
+ Itzam 1.1.0 released.
+
+ Added iterator selectors, which returns true or false for
+ a key. Only "true" keys will be included in the iterator
+ list. This allows the creation of subsets or filters -- for
+ example all odd numbers, or all names beginning with "S".
+
+ Fixed bug in itzam_btree_iterator_move_prev that prevented
+ reverse traversal of an index iterator.
+
+ A few minor internal names were changed for consistency's
+ sake.
+
+ The stress_btree test application is better documented and
+ commented. Use the -help option to see what all it does.
+
+18 April 2005
+ Initial 1.0.0 release
+
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