README CVector -- API for Dynamic Arrays

### CVector -- ANSI C API for Dynamic Arrays

Release 1.0.4.1
1 May 2018
© 2008, 2009, 2014 Herbert J. Bernstein
You may distribute the CVector API under the LGPL

CVector is an ANSI C implementation of dynamic arrays to provide a crude approximation to the C++ vector class.

Release 1.0.4.1 is a move from Sourceforge to Github. Release 1.0.4 adds a CMakeLists.txt file to the kit and changes the test program to allow normal output to be written to a specified file. Release 1.0.3 was is a minor revision of release 1.0.0 of 8 January 2009 to update the Makefile for builds under MINGW, on 26 February 2009 to add the macro CVectorElementAt, and on 7 July 2009 to change the macro to CVECTOR_FAR and similarly change the macros that handle memmove and memset. There are no changes to the code. The internal copy of libtool has been removed.

#### Installation

The CVector package is available on Github at https://github.com/yayahjb/cvector.

To see the current settings for a build execute

make

which should give the following information:

    PLEASE READ README_CVector.txt and lgpl.txt

     Before making the CVector library and example programs, check
     that the chosen settings are correct

     The current compile command is:

       libtool --mode=compile gcc -g -O2  -Wall -ansi -pedantic -I.  -c

     The current library link command is:

       libtool --mode=link  gcc -version-info 2:0:0 -release 1.0.4 -rpath /usr/local/lib

     The current library local, dynamic and static build commands are:

       libtool --mode=link gcc -g -O2  -Wall -ansi -pedantic -I.
       libtool --mode=link gcc -g -O2  -Wall -ansi -pedantic -shared -I /usr/local/include
       libtool --mode=link gcc -g -O2  -Wall -ansi -pedantic -static -I /usr/local/include

     Before installing the CVector library and example programs, check
     that the install directory and install commands are correct:

     The current values are :

       /usr/local
       libtool --mode=install cp

     To compile the CVector library and example programs type:

       make clean
       make all

     To run a set of tests type:

       make tests

     To clean up the directories type:

       make clean

     To install the library and binaries type:

       make install

If these settings need to be changed, edit Makefile. On some systems, e.g. Mac OS X, the default libtool is not appropriate. In that case you should install a recent version of libtool. The CVector kit has been tested with libtool versions 1.3.5, 1.5.4 and 2.2.6. If the system libtool is not to be used, define the variable LIBTOOL to be the path to the libtool executable, e.g. in bash. On MINGW, use of gcc 4 and libtool 2.2.6 are highly recommended.

export LIBTOOL=$HOME/bin/libtool

of in the Makefie

LIBTOOL = $(HOME)/bin/libtool

If you need to include local header files using #include "..." instead of #include <...>, define the variable USE_LOCAL_HEADERS

#### Synopsis

#include <CVector.h>

int
CVectorCreate(CVectorHandle * vectorhandle, const size_t elementsize, const size_t capacity);

int
CVectorAddElement(const CVectorHandle vectorhandle, const void * element);

void *
CVectorElementAt(const CVectorHandle vectorhandle, const size_t index);

int
CVectorGetElement(const CVectorHandle vectorhandle, void * element, const size_t index);

int
CVectorGetElementptr(const CVectorHandle vectorhandle, void ** elementptr, const size_t index);

int
CVectorSetElement(const CVectorHandle vectorhandle, void * element, const size_t index);

int
CVectorRemoveElement(const CVectorHandle vectorhandle, const size_t index);

int
CVectorClear(const CVectorHandle vectorhandle);

int
CVectorFree(CVectorHandle * vectorhandle);

size_t
CVectorCapacity(const CVectorHandle vectorhandle);

int
CVectorGetCapacity(const CVectorHandle vectorhandle, size_t * capacity);

size_t
CVectorSize(const CVectorHandle vectorhandle);

int
CVectorGetSize(const CVectorHandle vectorhandle, size_t * size);

int
CVectorGetFlags(const CVectorHandle vectorhandle, int * flags);

int
CVectorSetCapacity(const CVectorHandle vectorhandle, const size_t capacity);

int
CVectorSetSize(const CVectorHandle vectorhandle, const size_t size);

int
CVectorSetFlags(const CVectorHandle vectorhandle, const unsigned int flags);

#### Description

The CVector.h header file defines the CVectorHandle type as a dynamic array for elements in which each element uses elementsize characters in a block of memory elementsize*capacity characters long. There are size elements used in the array each with an index between 0 and size-1. CVectorCreate() is used to create the dynamic array. Elements may either be added at the end of the dynamic array using CVectorAddElement(), or in arbitrary order with CVectorSetElement(). Elements may be examined with copy semantics using CVectorGetElement() or as pointers directly into the dynamic array using CVectorGetElementptr(). The function CVectorElementAt() performs the same function as CVectorGetElementptr() for use in complex expressions, but does no error checking. Caution must be used in using pointers because expansion of the dynamic array can force relocation of all data in the dynamic array. Therefore, any use of CVectorGetElementptr() sets a flag, CVECTOR_FLAGS_NO_RELOCATION, that disables any further array relocation, which will prevent the extension of the size array beyond the capacity in effect at the time of the first CVectorGetElementptr() call. Calls to CVectorElementAt() do not set CVECTOR_FLAGS_NO_RELOCATION and returning resulting values to calling routines is dangerous. The functions CVectorGetFlags() and CVectorSetFlags() can be used to reset this flag (see Examples below). The function CVectorRemoveElement() will remove the element of the indicated index, shifting all elements of higher indices down, unless the flag CVECTOR_FLAGS_NO_RELOCATION is set. The capacity, size and flags may be examined or set with CVectorCapacity(), CVectorGetCapacity(), CVectorSize(), CVectorGetSize(), CVectorGetFlags, CVectorSetCapacity(), CVectorSetSize() and CVectorSetFlags().

External declarations as well as the CVector structure definition, and the CVectorHandle definition are included in the <CVector.h> include file. The CVector structure includes at least the following fields:

> size_t size; | /* size of the vector */
> size_t capacity; | /* capacity of the vector */
> size_t elementsize; | /* size of an element */
> void * array; | /* the array of elements */
> int flags; | /* flags */

The valid flags are CVECTOR_FLAGS_NO_RELOCATION and CVECTOR_FLAGS_NO_RESIZE which may be ORed.

#### Returns

The functions CVectorCapacity() and CVectorSize() are implemented as macros and return the CVector capacity and size directly. While they could be used as lvalues, such use is not recommended and is not guaranteed to work in future versions of CVector. The function CVectorElementAt() is implemented as a macro and returns a void * pointer into the data array with no bounds checking. All other functions return 0 for normal completion, or the sum of one or more of the following non-zero error codes:

> Error Return | Numeric Value | Meaning
> CVECTOR_MALLOC_FAILED | -1 | /* A call to allocate memory failed */
> CVECTOR_BAD_ARGUMENT | -2 | /* An argument is not valid */
> CVECTOR_NOT_FOUND | -4 | /* An element could not be found */
> CVECTOR_NO_RELOCATION | -8 | /* Relocation is not permitted */
> CVECTOR_NO_RESIZE | -16 | /* A change is size is not permitted */

#### Examples

To create a vector of doubles, starting with minimal capacity, reporting failure to stderr:

            #include <CVector.h>
            ...
            CvectorHandle vectorhandle;
            ...
            if (CVectorCreate(&vectorhandle,sizeof(double),1)) fprintf(stderr," CVectorCreate failed!!\n");

To create a vector of arrays of or pointers to doubles:

            #include <CVector.h>
            ...
            CvectorHandle vectorhandle;
            ...
            if (CVectorCreate(&vectorhandle,sizeof(double *),1)) fprintf(stderr," CVectorCreate failed!!\n");

To pop the last element of a vector of doubles:

            #include <CVector.h>
            ...
            CvectorHandle vectorhandle;
            double element;
            ...
            if (CVectorGetElement(vectorhandle, &element, (CVectorSize(vectorhandle)-1))
                fprintf(stderr," Failed CVectorGetElement);
            if (CVectorRemoveElement(vectorhandle,  (CVectorSize(vectorhandle)-1))
                fprintf(stderr," Failed CVectorRemoveElement);

See the test program CVectorBasicTest.c

Updated 1 May 2018