/*
$Id: pa_array.h,v 1.17 2001/02/21 17:36:29 paf Exp $
*/
/*
Array Chunk0
====== ========
head--------------->[ptr]
append_here-------->[ptr]
link_row ........
. .
. [ptr]
...........>[link to the next chunk]
*/
#ifndef PA_ARRAY_H
#define PA_ARRAY_H
#include <stddef.h>
#include "pa_pool.h"
#include "pa_types.h"
#include "pa_string.h"
class Array : public Pooled {
public:
typedef void Item;
enum {
CR_INITIAL_ROWS_DEFAULT=10,
CR_GROW_PERCENT=60
};
public:
Array(Pool& apool, int initial_rows=CR_INITIAL_ROWS_DEFAULT);
int size() const { return fused_rows; }
Array& operator += (Item *src);
Array& append_array(const Array& src);
Item *quick_get(int index) const {
// considering these true:
// index increments from 0 to size()-1
// index>=0 && index<size()
// index>=cache_chunk_base
// next chunk will be with "index" row
if(!(index<cache_chunk_base+cache_chunk->count)) {
int count=cache_chunk->count;
cache_chunk_base+=count;
cache_chunk=cache_chunk->rows[count].link;
}
return cache_chunk->rows[index-cache_chunk_base].item;
}
Item *get(int index) const;
void put(int index, Item *item);
const char *get_cstr(int index) const {
return static_cast<const char *>(get(index));
}
const String *get_string(int index) const {
return static_cast<const String *>(get(index));
}
private:
struct Chunk {
// the number of rows in chunk
int count;
union Row {
Item *item;
Chunk *link; // link to the next chunk in chain
} rows[1];
// next rows are here
}
*head; // the head chunk of the chunk chain
// last allocated chunk
// helps appending Arrays
Chunk *tail;
// next append would write to this record
Chunk::Row *append_here;
// the address of place where lies address
// of the link to the next chunk to allocate
Chunk::Row *link_row;
private:
// array size
int fused_rows;
mutable int cache_chunk_base;
mutable Chunk *cache_chunk;
private:
bool chunk_is_full() {
return append_here == link_row;
}
void expand(int chunk_rows);
private: //disabled
//Array(Array&) { }
Array& operator = (const Array&) { return *this; }
};
#endif
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