Proper class design

[Peter]

Hi,

I have a question about good class design ....

In my class I have some properties related to large amount
of data.
What is the best strategy, to include a reference to those
data (and making the object dependent on the client) or
copy the data into the object (independent object) ?

For example ....
class MyClass
{
int [] data; // reference to an int array .. no memory
alloc

(...)

// property Data
public Data
{
get
{
return data;
}
set
{
data = value;
}
}
}

and in the main method:

int [] large_data = new int[1000000];
MyClass myClass = new MyClass();
myClass.Data = large_data;

In this case the member "data" (via Property Data) refers to
"large_data" memory on the heap, like a C pointer.
At the other hand, if the "large_data" memory gets out of
scope, the object will no longer work, because of missing
data.

e.g.

MyClass myClass = new MyClass();
{
int [] large_data = new int[1000000];
myClass.Data = large_data;
}
// here, large_data is out of scope !!
int [] dd;
dd = myClass.Data; // data are missing ???

Some help would be nice.

Thanks,
Peter

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

Did you tried your example?

The memory will not be reclamed until no references are left.

MyClass myClass = new MyClass();
{
int [] large_data = new int[1000000];
myClass.Data = large_data;
}

as myClass is referencing the data it will not be reclamed.

which is the best way to create it , it does depend of how/who create the
data.

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"Peter" <An*****@work.nl> wrote in message
news:11***************@wgsvr01.wldelft.nl...

Hi,

I have a question about good class design ....

In my class I have some properties related to large amount
of data.
What is the best strategy, to include a reference to those
data (and making the object dependent on the client) or
copy the data into the object (independent object) ?

For example ....
class MyClass
{
int [] data; // reference to an int array .. no memory
alloc

(...)

// property Data
public Data
{
get
{
return data;
}
set
{
data = value;
}
}
}

and in the main method:

int [] large_data = new int[1000000];
MyClass myClass = new MyClass();
myClass.Data = large_data;

In this case the member "data" (via Property Data) refers to
"large_data" memory on the heap, like a C pointer.
At the other hand, if the "large_data" memory gets out of
scope, the object will no longer work, because of missing
data.

e.g.

MyClass myClass = new MyClass();
{
int [] large_data = new int[1000000];
myClass.Data = large_data;
}
// here, large_data is out of scope !!
int [] dd;
dd = myClass.Data; // data are missing ???

Some help would be nice.

Thanks,
Peter

[Sahil Malik]

In the first example, large_data does not get GC'ed unless myClass itself
goes out of scope as myClass is holding a reference to large_data.

- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik
"Peter" <An*****@work.nl> wrote in message
news:11***************@wgsvr01.wldelft.nl...

Hi,

I have a question about good class design ....

In my class I have some properties related to large amount
of data.
What is the best strategy, to include a reference to those
data (and making the object dependent on the client) or
copy the data into the object (independent object) ?

For example ....
class MyClass
{
int [] data; // reference to an int array .. no memory
alloc

(...)

// property Data
public Data
{
get
{
return data;
}
set
{
data = value;
}
}
}

and in the main method:

int [] large_data = new int[1000000];
MyClass myClass = new MyClass();
myClass.Data = large_data;

In this case the member "data" (via Property Data) refers to
"large_data" memory on the heap, like a C pointer.
At the other hand, if the "large_data" memory gets out of
scope, the object will no longer work, because of missing
data.

e.g.

MyClass myClass = new MyClass();
{
int [] large_data = new int[1000000];
myClass.Data = large_data;
}
// here, large_data is out of scope !!
int [] dd;
dd = myClass.Data; // data are missing ???

Some help would be nice.

Thanks,
Peter

[Peter]

Hi,

I must say I did not try the given example, but it's clear,
..NET is really very smart.

Thanks,
Peter

"Sahil Malik" <co*****************@nospam.com> wrote in
message news:%2****************@TK2MSFTNGP15.phx.gbl...

In the first example, large_data does not get GC'ed unless myClass itself goes out of scope as myClass is holding a reference to large_data.
- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik
"Peter" <An*****@work.nl> wrote in message
news:11***************@wgsvr01.wldelft.nl...

Hi,

I have a question about good class design ....

In my class I have some properties related to large amount of data.
What is the best strategy, to include a reference to those data (and making the object dependent on the client) or
copy the data into the object (independent object) ?

For example ....
class MyClass
{
int [] data; // reference to an int array .. no memory alloc

(...)

// property Data
public Data
{
get
{
return data;
}
set
{
data = value;
}
}
}

and in the main method:

int [] large_data = new int[1000000];
MyClass myClass = new MyClass();
myClass.Data = large_data;

In this case the member "data" (via Property Data) refers to "large_data" memory on the heap, like a C pointer.
At the other hand, if the "large_data" memory gets out of scope, the object will no longer work, because of missing data.

e.g.

MyClass myClass = new MyClass();
{
int [] large_data = new int[1000000];
myClass.Data = large_data;
}
// here, large_data is out of scope !!
int [] dd;
dd = myClass.Data; // data are missing ???

Some help would be nice.

Thanks,
Peter