dynamicArray.c

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/*==================================================================*\
|                EXIP - Embeddable EXI Processor in C                |
|--------------------------------------------------------------------|
|          This work is licensed under BSD 3-Clause License          |
|  The full license terms and conditions are located in LICENSE.txt  |
\===================================================================*/

#include "dynamicArray.h"
#include "memManagement.h"

errorCode createDynArray(DynArray* dynArray, size_t entrySize, uint16_t chunkEntries)
{
    void** base = (void **)(dynArray + 1);
    Index* count = (Index*)(base + 1);

    *base = EXIP_MALLOC(entrySize*chunkEntries);
    if(*base == NULL)
        return EXIP_MEMORY_ALLOCATION_ERROR;

    dynArray->entrySize = entrySize;
    *count = 0;
    dynArray->chunkEntries = chunkEntries;
    dynArray->arrayEntries = chunkEntries;

    return EXIP_OK;
}

errorCode addEmptyDynEntry(DynArray* dynArray, void** entry, Index* entryID)
{
    void** base;
    Index* count;

    if(dynArray == NULL)
        return EXIP_NULL_POINTER_REF;

    base = (void **)(dynArray + 1);
    count = (Index*)(base + 1);
    if(dynArray->arrayEntries == *count)   // The dynamic array must be extended first
    {
        size_t addedEntries;

        addedEntries = (dynArray->chunkEntries == 0)?DEFAULT_NUMBER_CHUNK_ENTRIES:dynArray->chunkEntries;

        if(*base == NULL)
        {
            *base = EXIP_MALLOC(dynArray->entrySize * addedEntries);
            if(*base == NULL)
                return EXIP_MEMORY_ALLOCATION_ERROR;
        }
        else
        {
            *base = EXIP_REALLOC(*base, dynArray->entrySize * (*count + addedEntries));
            if(*base == NULL)
                return EXIP_MEMORY_ALLOCATION_ERROR;
        }

        dynArray->arrayEntries = dynArray->arrayEntries + addedEntries;
    }

    *entry = (void*)((unsigned char *)(*base) + (*count * dynArray->entrySize));

    *entryID = *count;

    *count += 1;
    return EXIP_OK;
}

errorCode addDynEntry(DynArray* dynArray, void* entry, Index* entryID)
{
    errorCode tmp_err_code;
    void *emptyEntry;

    TRY(addEmptyDynEntry(dynArray, &emptyEntry, entryID));

    memcpy(emptyEntry, entry, dynArray->entrySize);
    return EXIP_OK;
}

errorCode delDynEntry(DynArray* dynArray, Index entryID)
{
    void** base;
    Index* count;

    if(dynArray == NULL)
        return EXIP_NULL_POINTER_REF;

    base = (void **)(dynArray + 1);
    count = (Index*)(base + 1);

    if(entryID == *count - 1)
    {
        *count -= 1;
    }
    else if(*count - 1 - entryID >= 0)
    {
        /* Shuffle the array down to fill the removed entry */
        memcpy(((unsigned char *)*base) + entryID * dynArray->entrySize,
               ((unsigned char *)*base) + entryID * dynArray->entrySize + dynArray->entrySize,
               (*count - 1 - entryID) * dynArray->entrySize);
        *count -= 1;
    }
    else
        return EXIP_OUT_OF_BOUND_BUFFER;

    return EXIP_OK;
}

void destroyDynArray(DynArray* dynArray)
{
    void** base = (void **)(dynArray + 1);
    EXIP_MFREE(*base);
}