CHANGES IN VERSION 1.22.0
-------------------------

NEW FEATURES

    o a new function `unload.gdsn()` to unload a GDS node from memory

UTILITIES

    o add '#pragma GCC optimize("O3")' to some of C++ files when GCC is used

    o add the compiler information in `system.gds()`

    o change the file name "vignettes/gdsfmt_vignette.Rmd" to "vignettes/gdsfmt.Rmd",
      so `vignette("gdsfmt")` can work directly

BUG FIXES

    o avoid the segfault if the data type is not registered internally

    o use O_CLOEXEC (the close-on-exec flag) when open and create files to avoid
      potentially leaking file descriptors in forked processes


CHANGES IN VERSION 1.20.0
-------------------------

UTILITIES

    o optimize the C implementation of 'packedreal8' using a look-up table

NEW FEATURES

    o new data types 'packedreal8u', 'packedreal16u', 'packedreal24u' and
      'packedreal32u'

BUG FIXES

    o the compression method 'LZ4_RA.max' does not compress data

    o `add.gdsn()` fails if a factor variable has no level

    o `add.gdsn(, storage=index.gdsn())` accepts the additional parameters from
      `index.gdsn()`, e.g., 'offset' and 'scale' for packedreal8


CHANGES IN VERSION 1.18.1
-------------------------

BUG FIXES

    o the node name should not contain a slash '/'


CHANGES IN VERSION 1.18.0
-------------------------

NEW FEATURES

    o new options 'recursive' and 'include.dirs' in `ls.gdsn()`: the listing
      recurses into child nodes

UTILITIES

    o replace BiocInstaller biocLite mentions with BiocManager

    o `digest.gdsn()` fails if the digest package is not installed

    o SIMD optimization in 2-bit array decoding with a logical vector of
      selection (3x speedup when there are lots of zeros)

BUG FIXES

    o bug fixed: `put.attr.gdsn()` fails to update the existing attribute


CHANGES IN VERSION 1.16.0
-------------------------

UTILITIES

    o a new storage name 'single' in `add.gdsn()` for single-precision
      floating numbers

    o improve the efficiency of bit2-unpacking when there are lots of zero

    o `system.gds()` outputs 'POPCNT' flag if available

    o enable the compression modes "LZMA.ultra", "LZMA.ultra_max",
      "LZMA_RA.ultra" and "LZMA_RA.ultra_max"

    o show more compression information in `system.gds()`

BUG FIXES

    o avoid the integer overflow when the compression rate is too small using
      LZMA_RA (e.g., < 0.01%)


CHANGES IN VERSION 1.14.0-1.14.1
-------------------------

UTILITIES

    o tweak error messages in `apply.gdsn()`

    o `cleanup.gds()` allows a file name with a prefix '~' which will be
      automatically replaced by the home directory


CHANGES IN VERSION 1.12.0
-------------------------

UTILITIES

    o update liblzma to v5.2.3

    o update lz4 to v1.7.5

    o a new citation


CHANGES IN VERSION 1.10.1
-------------------------

NEW FEATURES

    o new data types (variable-length encoding of signed and unsigned integers)


CHANGES IN VERSION 1.10.0
-------------------------

    o the version number was bumped for the Bioconductor release version 3.4


CHANGES IN VERSION 1.8.0-1.8.4
-------------------------

    o the version number was bumped for the Bioconductor release version 3.3

UTILITIES

    o define C MACRO 'COREARRAY_ATTR_PACKED' and 'COREARRAY_SIMD_ATTR_ALIGN'
      in CoreDEF.h

    o SIMD optimization in 1-bit and 2-bit array encoding/decoding (e.g.,
      decode, RAW output: +20% for 2-bit, +50% for 1-bit)


CHANGES IN VERSION 1.7.18-1.7.22
-------------------------

NEW FEATURES

    o LZMA compression algorithm is available in the GDS system (LZMA, LZMA_RA)

    o faster implementation of variable-length string: the default string
      becomes string with the length stored in the file instead of
      null-terminated string (new GDS data types: dStr8, dStr16 and dStr32)

UTILITIES

    o improve the read speed of characters (+18%)

    o significantly improve random access of characters

    o correctly interpret factor variable in `digest.gdsn()` when
      `digest.gdsn(..., action="Robject")`, since factors are not integers


CHANGES IN VERSION 1.7.0-1.7.17
-------------------------

NEW FEATURES

    o `digest.gdsn()` to create hash function digests (e.g., md5, sha1,
      sha256, sha384, sha512), requiring the package digest

    o new function `summarize.gdsn()`

    o `show()` displays the content preview

    o define C MACRO 'COREARRAY_REGISTER_BIT32' and 'COREARRAY_REGISTER_BIT64'
      in CoreDEF.h

    o new C functions `GDS_R_Append()` and `GDS_R_AppendEx()` in R_GDS.h

    o allows efficiently concatenating compressed blocks (i.e., ZIP_RA
      and LZ4_RA)

    o v1.7.12: add a new data type: packedreal24

    o define C MACRO 'COREARRAY_SIMD_SSSE3' in CoreDEF.h

    o v1.7.13: `GDS_Array_ReadData()`, `GDS_Array_ReadDataEx()`,
      `GDS_Array_WriteData()` and `GDS_Array_AppendData()` return `void*`
      instead of `void` in R_GDS.h

    o v1.7.15: `GDS_Array_ReadData()` and `GDS_Array_ReadDataEx()` allow
      Start=NULL or Length=NULL

    o v1.7.16: new C function `GDS_Array_AppendStrLen()` in R_GDS.h

UTILITIES

    o `paste(..., sep="")` is replaced by `paste0(...)` (requiring >=R_v2.15.0)

    o improve random access for ZIP_RA and LZ4_RA, e.g., in the example of
      vignette, +12% for ZIP_RA and 1.7-fold speedup in LZ4_RA

DEPRECATED AND DEFUNCT

    o bit17, ..., bit23, bit25, ..., bit31, sbit17, ..., sbit23, sbit25, ...,
      sbit31 are deprecated, and instead it is suggested to use data
      compression

BUG FIXES

    o v1.7.7: fix a potential issue of uninitialized value in the first
      parameter passed to 'LZ4_decompress_safe_continue' (detected by valgrind)

    o v1.7.14: fix an issue of 'seldim' in `assign.gdsn()`: 'seldim' should
      allow NULL in a vector


CHANGES IN VERSION 1.6.0-1.6.2
-------------------------

    o the version number was bumped for the Bioconductor release version 3.2

    o 'attribute.trim=FALSE' in `print.gdsn.class()` by default

NEW FEATURES

    o `diagnosis.gds()` returns detailed data block information

BUG FIXES

    o v1.6.2: it might be a rare bug (i.e., stop the program when getting
      Z_BUF_ERROR), now the GDS kernel ignores Z_BUF_ERROR in deflate()
      and inflate(); see http://zlib.net/zlib_how.html for further explanation


CHANGES IN VERSION 1.5.7-1.5.16
-------------------------

NEW FEATURES

    o a new argument 'seldim' in `assign.gdsn()`

    o `append.gdsn()` allows appending data from a GDS node

    o `add.gdsn()` allows 'storage' to be a 'gdsn.class' object

    o `put.attr.gdsn()` allows 'val' to be a 'gdsn.class' object

    o `readex.gdsn()` allows using numeric vectors to select the subset

    o the values returned from `read.gdsn()` and `readex.gdsn()` can be
      substituted by the values defined by users: '.value' and '.substitute'
      are added to `read.gdsn()` and `readex.gdsn()`

    o new functions `copyto.gdsn()`, `getfolder.gdsn()` and `permdim.gdsn()`

    o a new option 'replace+rename' in `moveto.gdsn()`

    o the values passed to the user-defined function in `apply.gdsn()` and
      `clusterApply.gdsn()` can be substituted by the values defined by users:
      '.value' and '.substitute' are added to these functions

    o new C functions `GDS_R_Obj_SEXP2SEXP()`, `GDS_Iter_RDataEx()`,
      `GDS_Iter_Position()`, `GDS_Parallel_TryLockMutex()`,
      `GDS_Parallel_InitCondition()`, `GDS_Parallel_DoneCondition()`,
      `GDS_Parallel_SignalCondition()`, `GDS_Parallel_BroadcastCondition()` and
      `GDS_Parallel_WaitCondition()` in "include/R_GDS.h"

    o new arguments 'attribute' and 'attribute.trim' in `print.gds.class()`
      and `print.gdsn.class()`

    o `delete.attr.gdsn()` allows multiple variable names

    o gdsfmt_1.5.16: hidden flag is an internal flag along with 'R.invisible',
      `objdesp.gdsn()` returns the hidden flag

DEPRECATED AND DEFUNCT

    o discontinue the support of SNPRelate (<= v0.9.*)

    o `GDS_R_NodeValid()` and `GDS_R_NodeValid_SEXP()` are removed from
      "include/R_GDS.h"

    o `GDS_R_SEXP2Obj()` in "include/R_GDS.h" has two arguments now

BUG FIXES

    o fix an issue in `print.gdsn.class()` if hidden nodes are included

    o fix the issues #3 (https://github.com/zhengxwen/gdsfmt/issues/3)
      and #11 (https://github.com/zhengxwen/gdsfmt/issues/11)

    o fix a portable issue on Windows when calling a condition object
      (dPlatform.h/dPlatform.cpp)

    o fix a compiling issue on Solaris with suncc

    o fix an issue of additional arguments in `add.gdsn()`,
      https://github.com/zhengxwen/gdsfmt/issues/12

    o fix an issue of uncompressing variable-length string,
      https://github.com/zhengxwen/gdsfmt/issues/13


CHANGES IN VERSION 1.5.0-1.5.6
-------------------------

NEW FEATURES

    o LZ4 library is updated to r131

    o a new argument 'include.hidden' is added to the functions `cnt.gdsn()`
      and `ls.gdsn()`

    o define `GDS_MAX_NUM_DIMENSION` and `GDS_R_READ_DEFAULT_MODE` in
      "include/R_GDS.h"

    o a new C function `GDS_R_SEXP2FileRoot()` in "include/R_GDS.h"

    o improve the terminal output via the package crayon

UTILITIES

    o adjust for Xcode 6.3.1

    o increase test coverage

BUG FIXES

    o fix an issue in `append.gdsn()`,
      https://github.com/zhengxwen/gdsfmt/issues/9

    o fix an issue in `assign.gdsn()`,
      https://github.com/zhengxwen/gdsfmt/issues/10


CHANGES IN VERSION 1.4.0
-------------------------

    o the version number was bumped for the Bioconductor release version 3.1


CHANGES IN VERSION 1.3.0-1.3.11
-------------------------

NEW FEATURES

    o a new argument 'visible' is added to the functions `add.gdsn()`,
      `addfile.gdsn()` and `addfolder.gdsn()`

    o `objdesp.gdsn()` returns 'encoder' to indicate the compression algorithm

    o add a new function `system.gds()` showing system configuration

    o support efficient random access of zlib compressed data, which are
      composed of independent compressed blocks (ZIP_RA)

    o support LZ4 compression format (http://code.google.com/p/lz4/),
      based on "lz4frame API" of r128

    o allow R RAW data (interpreted as 8-bit signed integer) to replace
      32-bit integer with `read.gdsn()`, `readex.gdsn()`, `apply.gdsn()`,
      `clusterApply.gdsn()`, `write.gdsn()`, `append.gdsn()`

    o a new argument 'target.node' is added to `apply.gdsn()`, which allows
      appending data to a target GDS variable

    o `apply.gdsn()`, `clusterApply.gdsn()`: the argument 'as.is' allows
      "logical" and "raw"

    o more argument checking in `write.gdsn()`

    o new components 'trait' and 'param' in the return value of `objdesp.gdsn()`

    o add new data types: packedreal8, packedreal16, packedreal32

    o a new argument 'permute' in the function `setdim.gdsn()`

SIGNIFICANT USER-VISIBLE CHANGES

    o add a R Markdown vignette

BUG FIXES

    o minor fixes

    o fix an issue of variable-length string,
      https://github.com/zhengxwen/gdsfmt/issues/7

    o minor fixes, `sync.gds()` synchronizes the GDS file

    o fix a stream read error bug, https://github.com/zhengxwen/gdsfmt/issues/6

    o fix an issue in `add.gdsn()`, https://github.com/zhengxwen/gdsfmt/issues/8

    o fix the problem of `setdim.gdsn()` with variable-length string


CHANGES IN VERSION 1.1.0
-------------------------

NEW FEATURES

    o add a new function `is.element.gdsn()`

    o allow closing GDS files in `showfile.gds()`

BUG FIXES

    o fully support big-endian systems

    o fix memory leaks in `cleanup.gds()`


CHANGES IN VERSION 1.0.4
-------------------------

NEW FEATURES

    o `apply.gdsn()` and `clusterApply.gdsn()` support characters

    o add a new function `moveto.gds()` to relocate GDS variables

    o add a new function `diagnosis.gds()` to diagnose the GDS file

SIGNIFICANT USER-VISIBLE CHANGES

    o `apply.gdsn()`, `clusterApply.gdsn()`: make the returned value invisible
      if 'as.is="none"'

    o more options in `read.gdsn()` and `readex.gdsn()`

    o more Unit tests

BUG FIXES

    o fix a bug in `delete.gdsn()`: allocated resource is not released
      in the GDS file


CHANGES IN VERSION 1.0.3
-------------------------

NEW FEATURES

    o add two new arguments 'allow.duplicate' and 'allow.fork' to the
      function `openfn.gds()`

    o add a new function 'showfile.gds'

    o allow reading a GDS file simultaneously between multiple forked
      processes (applied in `mclapply()` etc)

    o support the LinkingTo mechanism, via 'R_RegisterCCallable' and
      'R_GetCCallable'


CHANGES IN VERSION 1.0.2
-------------------------

NEW FEATURES

    o add 'size' and 'good' to the returned list from `objdesp.gdsn()`
      indicating the state of GDS node

    o add a new function 'cache.gdsn'

BUG FIXES

    o fix the memory issues reported by valgrind


CHANGES IN VERSION 1.0.1
-------------------------

NEW FEATURES

    o add a new argument 'replace' to the function `addfile.gdsn()`, which
      allows replacing the existing variable by a new one

    o add a new function `addfolder.gdsn()` allowing a virtual folder linking
      to other GDS files

    o add 'message' to the returned list from `objdesp.gdsn()`, which allows
      tracking error messages or log information

SIGNIFICANT USER-VISIBLE CHANGES

    o remove the argument 'deep' from the function `cleanup.gds()` to
      simplify calling

    o reduce the package size

BUG FIXES

    o backward compatible with unknown or undefined classes in GDS system


CHANGES IN VERSION 1.0.0
-------------------------

NEW FEATURES

    o support long vectors (>= R v3.0), allowing >4G (memory size)
      vectors in R

    o ~20x speedup in reading characters from a GDS file, compared to
      the previous version

    o add a new argument 'replace' to the function `add.gdsn()`, which allows
      replacing the existing variable by a new one

    o add a new argument 'simplify' to the functions `read.gdsn()` and
      `readex.gdsn()`

SIGNIFICANT USER-VISIBLE CHANGES

    o speed improvement for other primitive data types

    o a warning is given, when a variable with missing characters is written
      to a GDS variable

    o replace all '.C()' by '.Call()' internally

    o reduce the package size

BUG FIXES

    o improve the function `objdesp.gdsn()`

    o fix a bug in `delete.gdsn()`


CHANGES IN VERSION 0.9.13-0.9.15
-------------------------

BUG FIXES

    o fix an issue of memory leak when a compressor or decompressor is loaded

    o fix an error in the CITATION file

    o compiler issue fix: Solaris 10

    o use 'inherits' to check the inheritance of object install 'class() =='


CHANGES IN VERSION 0.9.12
-------------------------

NEW FEATURES

    o support variable-length string (e.g., VStr8)

SIGNIFICANT USER-VISIBLE CHANGES

    o add an argument 'path' to the function `index.gdsn()`, which uses
      '/' as a separator

    o support a faster defragmentation algorithm in `cleanup.gds()`

    o 'character' in the function `add.gdsn()` refers to variable-length
      string by default

    o fixed-length strings are "fstring", "fstring16" and "fstring32" in
      the function `add.gdsn()`

    o variable-length string are 'string', 'string16' and 'string32' in
      the function `add.gdsn()`

    o support the 'R.invisible' attribute to hide a GDS node, until
      adding 'all=TRUE' to `print.gds.class()` or `print.gdsn.class()`

    o improve the display of hierarchical structure

    o the argument "storage" in the function `add.gdsn()` is not
      case-sensitive now

BUG FIXES

    o minor bug fix in `readex.gdsn()` when 


CHANGES IN VERSION 0.9.11
-------------------------

NEW FEATURES

    o `put.attr.gdsn()` allows a vector with more than one elements

SIGNIFICANT USER-VISIBLE CHANGES

    o it is more efficient to store a factor variable

    o `apply.gdsn()` is re-written in C/C++

    o the function `applylt.gdsn()` is merged into `apply.gdsn()`

    o the function `clusterApplylt.gdsn() is merged into `clusterApply.gdsn()`

    o improve `clusterApply.gdsn()`

    o S3 class name 'gdsclass' is replaced by 'gds.class'

    o S3 class name 'gdsn' is replaced by 'gdsn.class'

DEPRECATED AND DEFUNCT

    o deprecate `applylt.gdsn()` and `clusterApplylt.gdsn()`

BUG FIXES

    o bug fix: add a folder using `add.gdsn()`


CHANGES IN VERSION 0.9.1-0.9.10
-------------------------

NEW FEATURES

    o add two functions with the support of the parallel package (R 2.14.0):
      `clusterApply.gdsn()`, `clusterApplylt.gdsn()`

SIGNIFICANT USER-VISIBLE CHANGES

    o change 'wstring' to 'string16' in `add.gdsn()`

    o change 'dwstring' to 'string32' in `add.gdsn()`

    o add RUnit tests

    o support GCC4.7 compiler

BUG FIXES

    o fix warnings

    o fix a bug: correct the dimension size of array data with more
      than two dimensions

    o fix bugs: 'append.gdsn' appends data of bit9, bit10, etc, correctly

    o fix a minor bug of compression stream


CHANGES IN VERSION 0.9.0
-------------------------

    o first release of gdsfmt
