Version 1.3.1 (10 March 2011)

* Possibly breaking changes
  - No longer open syscall files with O_SYNC|O_DSYNC|O_RSYNC by default when
    doing direct I/O, to avoid a write performance decrease starting with Linux
    kernel version 2.6.32.
    A stxxl::file::SYNC flag has been added to allow forcing the O_*SYNC flags
    when opening files.
  - Lock files by default (if implemented for this file type), can by disabled
    via stxxl::file::NO_LOCK.
  - block_prefetcher now takes a completion_handler instead of a raw function
    pointer.  Furthermore, the completion_handler is already executed after the
    read operation completes, not only when the issuer waits for it to
    complete.  The I/O thread issues the call to the completion_handler, so for
    multiple disks, this may happen concurrently.
* Internal changes, not user-visible
  - Change handling of (empty) filler elements in typed_block to fix
    mismatching struct size in nested blocks.
  - Removed debugmon which was very limited and disabled for a long time.
* Bugfixes
  - Allow prefetch schedule computation of vectors that are bound to a file.
  - Fix race growing files during concurrent block allocation.
  - Allow reading a block that spans over end-of-file, fill remainder with
    zeroes.
  - Crash at program termination when using global stxxl containers.
  - Enable syscall_file to read/write >=2GiB of data in a single I/O operation.
* New public headers: stxxl/stats, stxxl/request
* Parallel mode can be switched on for internal STXXL computation selectively
  (i.e. without enabling it for the non-stxxl part of an application), by
  setting USE_PARALLEL_MODE=yes in make.settings.local.
* Platform Support
  - add ICPC 12.0, works with both MCSTL (needs libstdc++ from GCC 4.2) and
    parallel mode (needs libstdc++ from GCC 4.3 (not 4.4/4.5))
  - add CLANG++ 2.8
  - add MSVC 2010/Windows 7
  - allow the library name generated by MSVC to be changed by setting LIBNAME
    and redefining STXXL_LIBNAME (defaults to "stxxl")
* Under-the-hood improvements
  - code cleanup
  - I/O-layer: renaming and reorganization of the request implementation
* Documentation updates
* Several new test programs
* Several test programs improved

------------------------------------------
Version 1.3.0 (12 August 2010)

* New file types
  - fileperblock_syscall/fileperblock_mmap/fileperblock_boostfd/fileperblock_wincall:
    Use a separate file for each block, which is accessed by means of the
    underlying file type.  The "filename" given is used as a prefix of the
    block file names.  The advantage of these file types is that unused
    disk space is freed earlier on the file system level.
  - wbtl_file:  Do library-based write-combining (good for writing small blocks onto SSDs)
* I/O subsystem
  - separate the disk number of a file (which queue to put requests in)
    from the fact that blocks for this file are allocated via the block
    manager (disk number -1 otherwise).
  - separate wait time counting for read and write I/Os
  - wait times can be logged to a separate log file
    (compile with -DSTXXL_WAIT_LOG_ENABLED and set STXXLWAITLOGFILE in the environment)
* Parallel PQ
  - priority_queue now supports parallelized operations utilizing the libstdc++ parallel mode
* Other new functionality
  - file requests can now be canceled (success not guaranteed), completion handlers are called anyway.
  - log file locations are now configurable by the environment variables
    STXXLLOGFILE and STXXLERRLOGFILE
  - single queue I/O scheduling
  - reverse_iterator added to containers types vector, deque and map
  - autogrow files (specified in .stxxl by a size of 0), will be deleted on normal program termination
  - add infrastructure to build multiple binaries with different CXXFLAGS from a single source
  - overwriting deleted memfile regions with uninitialized data is now optional
    (STXXL_CLEAR_FREE_MEMFILE_MEM)
  - read_write_pool that combines prefetch_pool with write_pool and ensures cache coherency
  - add a replaceable exit handler implementation, can be overwritten e.g. for library inclusion
* Many, many bug fixes, in particular concerning
  - priority queue
  - optimal prefetch schedule
  - possible race condition while creating singleton instances
  - random_shuffle()
* Platform Support
  - add GCC 4.4 (parallel mode features not working in GCC 4.3 can now be used)
  - add GCC 4.5
  - initial support for GCC 4.6
  - add ICPC 11.x
  - add Boost 1.42
  - add FreeBSD
  - drop Solaris
* New benchmarks
  - io/benchmark_disks: more command line paramaters for finer testing granularity
  - measure hard-disk and flash-disk combined performance and
    determine best block size pairs (io/benchmark_disk_and_flash)
  - benchmark using regular STXXL configuration (benchmark_configured_disks)
* Possibly breaking changes
  - API name changes
    vector::touch -> vector::block_externally_updated
  - Template parameter changes
    stream::sorted_runs, trigger_entry, trigger_entry_cmp, trigger_entry_iterator
  - Priority of write changes
  - Other name changes (considered internal)
    typed_block<>::has_filler -> !typed_block<>::has_only_data
    file::delete_region -> file::discard
    vector::alloc_strategy -> vector::alloc_strategy_type
  - stxxl::sort(..., M) and stxxl::stream::sort(..., M) now adhere to to the memory limit M
    more strictly and throw errors instead of overallocating
  - Execute completion handler before notifying waiters, so far after.
* Deprecated methods:
  - stxxl::stats::reset(), stxxl::stats::_reset_io_wait_time():
    use stxxl::stats_data instead to store snapshots of the counters and compute differences
* Under-the-hood improvements
  - I/O layer cleanup
  - aligned_alloc
* Doxy now also lists undocumented members
* stop requiring STXXL_ROOT to be a hard coded absolute path set in make.settings.local,
  a default of CURDIR works fine
* document #defines in defines.h
  - switch on/off file types with STXXL_HAVE_xxx_FILE (to avoid platform compatibility problems)

------------------------------------------
Version 1.2.1 (14 August 2008)

* add support for the libstdc++ parallel_mode (successor of MCSTL),
  new make targets: library_g++_pmode, tests_g++_pmode, clean_g++_pmode
  (requires g++ 4.3.2 or later)
* new stxxl file type stxxl::mem_file (for debugging purposes only),
  helps debugging with valgrind because no memory cell ever
  leaves valgrind's control
* properly destroy the singleton objects (block manager, disk queue threads,
  logger, stats, config, ...) at program exit
* fixed a bug (recursive locking) in recursive block allocation
* added a test program for recursive block allocation
* sensible dependencies for nmake (MSVC): only rebuild files as necessary
* improve performance of createdisks
* human-readable output for I/O stats
* replace hard coded min/max values by std::numeric_limits<>::min/max in
  examples
* fix a case where only half of the available memory was used during
  recursive merging
* verify stxxl::set_seed() functionality in tests
* remove stxxl disk files created from default configuration (no .stxxl
  file found) and other temporary files at program end
* stop using deprecated functions, switch to the replacements instead
* unify the mutex lock handling by introducing stxxl::scoped_mutex_lock
* unify the I/O wait time counting to work like read/write time counting
* simplify I/O time counting with scoped_{read,write,wait}_timer
* add some more tests
* more code cleanup + reformatting
* move some more code to the library
* reduce some include dependencies
* build system tuning
* propagate region deletion (when blocks are freed) to the file level
* fix problem in sorters where blocks were released too early
* specialize is_sorted() to use const_vector_iterators, no extra writes
* add c++0x style const_iterator cbegin()/cend() to all containers

------------------------------------------
Version 1.2.0 (05 July 2008)

* made the block management layer thread-safe
* made all size_types unsigned
* stxxl::priority_queue
  - fixed a rare assertion
  - fixed a race condition by using proper block hinting
  - insert_queue: replaced std::priority_queue with a special
    implementation internal_priority_queue that allows for
    fast exporting of all elements
  - even more bugs and inefficiencies fixed
  - significant speed improvements
* random number generators are now all seedable,
  should allow redoing identical program runs for debugging purposes
* stxxl::noncopyable, inspired by boost::noncopyable: inheriting from this
  class forbids copying of objects when this is undesirable
  - used in all classes that had implemented their own variants previously
* stxxl::vector, all sorting functions: replaced TwoToOneDimArrayRowAdaptor
  with ArrayOfSequencesIterator which is much faster, especially
  if blocks have padding
* if required, verify that the sentinels satisfy a strict weak ordering
* stxxl::vector: several operations sped up, several more implemented
* fix existing allocation strategies and add experimental support for
  distinguishing between regular disks and flash devices
* stxxl::stable_ksort
  - add experimental warning, some parts are not yet implemented
  - fixed an off-by-one error in memory allocation vs. usage
* btree: fuse last two nodes/leaves if possible, rebalancing can fail
* btree tests: ensure uniqueness of test data if required
* reduce function call overhead of stxxl::debugmon if it's not activated
* add public interface headers: stxxl/types, stxxl/aligned_alloc
* add compatibility wrappers for standard extensions
  hash_map, hash_set, auto_ptr
* MCSTL is only supported with g++ 4.2 and icpc 10.x
* lots of small bugfixes
* made the TPIE, BDB and LEDA_SM tests compile again
* general code cleanup
  - fixed most compiler warnings
  - elimination of duplicate and unused code
  - cleaned up and sanitized debugging macros
  - no more 'using namespace std' and 'using namespace stxxl'
  - fixed ambiguities noted by g++ 4.3
  - unify the #include directives
  - add/unify/cleanup copyright headers
* general code reformatting (uncrustify)
* add support for new compiler releases
* portability fixes for different platforms
* implemented file truncation on windows platforms
* build system
  - lots of small modifications
  - now only requires GNU make 3.78 or later
  - check whether STXXL_ROOT has been set correctly and if unset, try
    autoconfiguration by creating make.settings.local with defaults
  - improved and simplified boost support for posix systems
  - Mac OS X support
* changed all tests so that they behave well in their default parameters,
  system assumptions and return values and can be run from a script
  - use aligned_alloc/aligned_dealloc appropriately
* added some more test programs
* add misc/run_all_tests that runs all tests with sensible parameters,
  optionally via valgrind
* checked all tests with valgrind
  - fixed use of uninitialized memory when writing to normal files
  - (optionally) initialize typed_blocks and payload data in test structs
    to suppress (most) uninitialized write errors when writing to disk files
  - fix mismatched new/delete in mcstl
* update install and usage instructions
* spell checked sources and documentation

------------------------------------------
Version 1.1.0 (31 July 2007)

* stxxl is now hosted on SourceForge: http://stxxl.sourceforge.net/
* Restructured the source layout:
  - includes moves to include/
  - introduced some public headers:
    stxxl.h, stxxl/algorithm, stxxl/bits, stxxl/deque, stxxl/io, stxxl/ksort, stxxl/mallocstats, stxxl/map, stxxl/mng, stxxl/priority_queue, stxxl/queue, stxxl/random, stxxl/scan, stxxl/sort, stxxl/stable_ksort, stxxl/stack, stxxl/stream, stxxl/timer, stxxl/vector
  - the header "stxxl" is no longer available, please use "stxxl.h" instead
  - the use of any other (internal) header is discouraged, additional public headers can be added as the need arises
* Overhauled the build system:
  - merged configuration files, simplified option tuning
  - support object files and binaries with and without mcstl support existing in parallel
  - the library build creates stxxl.mk which can be included in an applications Makefile to set the correct compiler/linker switches for stxxl
  - similarly mcstxxl.mk is created for a stxxl compiled with mcstl support
  - add dependency tracking and improve parallelism during build
* compiler support matrix: (for an up-to-date list, please see the doxygen documentation)
  compiler      |  stxxl    stxxl + mcstl
  --------------+------------------------
  GCC 4.3       |    x            x
  GCC 4.2       |    x            x
  GCC 4.1       |    x           n/a
  GCC 4.0       |    x           n/a
  GCC 3.4       |    x           n/a
  GCC 3.3       |    o           n/a
  GCC 2.95      |    -           n/a
  ICPC 9.1.051  |    x            x¹
  ICPC 10.0.025 |    x            x¹
  MSVC 2005 8.0 |    x           n/a
    x = full support   o = partial support   - = unsupported
    n/a = compiler does not support OpenMP which is needed by MCSTL
      ¹ = does not work with STL GCC 4.2.0 (ICPC bug), workaround:
          the first include in the program must be
          "stxxl/bits/common/intel_compatibility.h"
* pipelined stream::sort, stream::runs_creator and stream::runs_merger are parallelized using MCSTL
* obsolete files removed
* fixed include dependencies
* fixed lots of warnings
* fixed lots of small bugs
* add header compilation tests
* stxxl::vector: implemented some more functions
* const char* stxxl::get_version_string(): new function
* comparators inherit from std::binary_function<>
* cleanup, reformat the code to a consistent format (Thanks, uncrustify!)

------------------------------------------
Version 1.0e (4 June 2007)

* Bugfix: for objects with the destructors, memory block were allocated in a non-aligned fashion
* Internal CPU efficiency of Stxxl priority queue is improved (loser trees in external mergers are integrated)
* Fixed bug with conversion of const/non-const iterators, implemented comparison and difference operations on const/non-const iterators (for vector, map, and deque)
* Added operator[] to vector and deque iterators
* stxxl::random_shuffle added
* improved Makefile structure (thanx to Andreas Beckmann)
* Allow parallel build for g++

------------------------------------------
Version 1.0d (16 January 2007)

* Support of Visual Studio 2005 Express (VC++ 8.0)

* Algorithms and data structures of Stxxl can now use more than 4GB of main memory on 64-bit processors/compilers

* Support of error reporting using the C++ exception mechanism

-------------------------------------------
Version 1.0c (21 September 2006)

* An implementation of an I/O-efficient deque

* STXXL uses MCSTL library (optional) to improve the performance of stxxl::sort and pipelined sort on SMP and multicore processors.

-------------------------------------------
Version 0.99 (22 March 2006)

* Better compiler support: g++ (versions 3.3.x-4.0.x) and Microsoft Visual C++ 7.1 (.NET)

* New B+Tree-based implementation of map (compatible with all listed above compilers): I/O-efficient map

------------------------------------------
Version 0.9 (9 August 2005)

* STXXL has been ported to Windows. It now can be run under Windows XP and Windows 2000

* STXXL can be compiled now by g++ (versions 3.0.x-3.4.x, 4.0.x) and Microsoft Visual C++ 7.1 (.NET)

* New data structure: I/O efficient FIFO queue

------------------------------------------
Version 0.77 (24 March 2005)

* An implementation of queue is available

------------------------------------------
Version 0.75 (23 March 2005)

* An implementation of map based on B+tree is available

------------------------------------------
Version 0.7 (25 January 2005)

* The implementation of pipelining is extended and improved

------------------------------------------
Version 0.6 (5 September 2004)

* Tested implementation of the stream package (aka pipelining) is available

------------------------------------------
Version 0.5 (21 November 2003)

* The first implementation of the stream package (aka pipelining) is available

* Priority queue is available

------------------------------------------
Version 0.2 (Summer 2003)

* The first public release

* Vectors, stacks, sorting, scanning are available






