Apex Multi-Dimensional Array Padding Performance Test

amdappt.java

/**
 * @description Testing script for padding multi-dimensional arrays in Salesforce Apex
 * @author      Justus van den Berg (jfwberg@gmail.com)
 * @url         https://medium.com/@justusvandenberg/salesforce-apex-optimization-maps-vs-multi-dimensional-arrays-lists-3703b9aaaf79
 * @note        Execute anonymous script, performance depends on the time of day and org it runs on
*/
// Test Settings
Integer numX = 90;
Integer numY = 90;
Integer numZ = 90;

// Class level variables
Integer     sizeX = 0;
Integer[]   sizeY = new Integer[]{};
Integer[][] sizeZ = new Integer[][]{};

// Execute the data orchestration
orchestrateData();

// Simple orchestration method
void orchestrateData(){
        
    // Create a three dimentional array
    Entity[][][] entities = new Entity[][][]{};

    // Apply pre-padding with max values
    padArray(entities,numX,numY,numZ);
    
    // Register timings
    Integer st = Limits.getCpuTime();
    Integer sh = Limits.getHeapSize();
    setEntityTest(entities);
    Integer eh = Limits.getHeapSize();
    Integer et = Limits.getCpuTime();
    getEntityTest(entities);
    Integer feh = Limits.getHeapSize();
    Integer fet = Limits.getCpuTime();

    // Output the numbers
    System.debug('Number of entities : ' + (numX * numY * numZ));
    System.debug('CPU Time  SET      : ' + (et-st));
    System.debug('Heap Used SET      : ' + ((Decimal)((eh -sh)/1000)).format() + ' KB');
    System.debug('CPU Time  GET      : ' + (fet-et));
    System.debug('Heap Used GET      : ' + ((Decimal)((feh-eh)/1000)).format() + ' KB');
}


// Method for testing the getter
void getEntityTest(Entity[][][] entities){
    for(Integer x=0;x<numX;x++){
        for(Integer y=0;y<numY;y++){
            for(Integer z=0;z<numZ;z++){
                Entity e = entities[x][y][z];
            }
        }
    }
}


// Method for testing the setter
void setEntityTest(Entity[][][] entities){
    for(Integer x=0;x<numX;x++){
        for(Integer y=0;y<numY;y++){
            for(Integer z=0;z<numZ;z++){
                setEntity(entities, x, y, z);
            }
        }
    }
}


/**
 * Method that adds an object at a specific location in the array
 */
void setEntity(Entity[][][] entities, Integer x, Integer y, Integer z){
    
        // Check if the X cooridinate is out of bounds in the entities lists
    if(x >= sizeX){
        
        // Start at the last index of the entities lists and add a child list
        // for each index that is out of bounds
        for(Integer i = sizeX-1; i < x; i++){
            entities.add(new Entity[][]{});
            
            // Update the value in sizeX
            sizeX++;
            
            // Start the counter for each Y coordinate
            sizeY.add(0);
            sizeZ.add(new Integer[]{});
        }    
    }
    
    // Check if the Y cooridinate is out of bounds in the entites[x] list
    if(y >= sizeY[x]){
        
        // Store the current size, this is faster than referencing the counter array all the time
        Integer currentSizeY = sizeY[x];
        
        // Start at the last index of the entities[x] lists and add a child list
        // for each index that is out of bounds
        for(Integer i = sizeY[x]-1; i < y; i++){
            entities[x].add(new Entity[]{});
            
            // Increment the current size
            currentSizeY++;
            
            // Start the counter for the 
            sizeZ[x].add(0);
        }
        
        // update the size array with the new value
        sizeY[x] = currentSizeY;
        
    }

    // Check if the Z cooridinate is out of bounds in the entites[x][y] list
    if(z >= sizeZ[x][y]){
        
        // Store the current size, this is faster than referencing the counter array all the time
        Integer currentSizeZ = sizeZ[x][y];
        
        // Start at the last index of the entities[x][y] lists and add a NULL value
        // for each index that is out of bounds
        for(Integer i = sizeZ[x][y]-1; i < z; i++){
            entities[x][y].add(null);
            currentSizeZ++;
        }
        
        // Update te
        sizeZ[x][y] = currentSizeZ;
    }

    // Add the entity to the array
    entities[x][y][z] = new Entity(x,y,z);
}


// Method for padding the array
void padArray(Entity[][][] entities, Integer x, Integer y, Integer z){

    // Check if the X cooridinate is out of bounds in the entities lists
    if(x >= sizeX){
        
        // Start at the last index of the entities lists and add a child list
        // for each index that is out of bounds
        for(Integer i = sizeX-1; i < x; i++){
            entities.add(new Entity[][]{});
            
            // Update the value in sizeX
            sizeX++;
            
            // Start the counter for each Y coordinate
            sizeY.add(0);
            sizeZ.add(new Integer[]{});
        }    
    }
    
    // Check if the Y cooridinate is out of bounds in the entites[x] list
    if(y >= sizeY[x]){
        
        // Store the current size, this is faster than referencing the counter array all the time
        Integer currentSizeY = sizeY[x];
        
        // Start at the last index of the entities[x] lists and add a child list
        // for each index that is out of bounds
        for(Integer i = sizeY[x]-1; i < y; i++){
            entities[x].add(new Entity[]{});
            
            // Increment the current size
            currentSizeY++;
            
            // Start the counter for the 
            sizeZ[x].add(0);
        }
        
        // update the size array with the new value
        sizeY[x] = currentSizeY;
        
    }

    // Check if the Z cooridinate is out of bounds in the entites[x][y] list
    if(z >= sizeZ[x][y]){
        
        // Store the current size, this is faster than referencing the counter array all the time
        Integer currentSizeZ = sizeZ[x][y];
        
        // Start at the last index of the entities[x][y] lists and add a NULL value
        // for each index that is out of bounds
        for(Integer i = sizeZ[x][y]-1; i < z; i++){
            entities[x][y].add(null);
            currentSizeZ++;
        }
        
        // Update te
        sizeZ[x][y] = currentSizeZ;
    }
}


/**
 * Basic class example of a cell
 */
class Entity{
    
    Integer x;
    Integer y;
    Integer z;

    Entity(Integer x, Integer y, Integer z){
        this.x = x;
        this.y = y;
        this.z = z;
    }
}