dbTimeSeriesBlock Class Template Reference

#include <timeseries.h>

List of all members.

---

Detailed Description

template<class T>
class dbTimeSeriesBlock< T >

Time series block contaning array of elements.

Grouping several elements in one block (record) reduce space overhead and increase processing speed.
Attention! This class is not serialized, so it is can be accessed only by one thread

You are defining your own time series class, for example:

 class Stock {
   public:
     char const* name;
     TYPE_DESCRIPTOR((KEY(name, INDEXED)));
 };

 class Quote {
   public:
     int4        tickerDate;
     real4       bid;
     int4        bidSize;
     real4       ask;
     int4        askSize;

     time_t time() const { return tickerDate; } // this method should be defined

     TYPE_DESCRIPTOR((FIELD(tickerDate), FIELD(bid), FIELD(bidSize), FIELD(ask), FIELD(askSize)));
 };
 typedef dbTimeSeriesBlock<Quote>  DailyBlock;
 REGISTER(DailyBlock);
 

Now you can work with time series objects in the followin way:

 dbDatabase db;
 if (db.open("mydatabase.dbs")) {
     dbTimeSeriesProcessor<Quote> proc(db, MIN_ELEMENTS_IN_BLOCK,MAX_ELEMENTS_IN_BLOCK);
     Quote quote;
     // initialize quote
     Stock stock;
     stock.name = "AAD";
     oid_t stockId = insert(oid).getOid();
     proc.add(stockId, quote); // add new element in time series

     Quote quoteBuf[MAX_QUOTES];
     // select quotes for the specified interval
     int n = proc.getInterval(stockId, fromDate, tillDate, quoteBuf, MAX_QUOTES);
     for (int i = 0; i < n; i++) {
         printf("bid=d ask=%d\n", quoteBuf[i].bid, quoteBuf[i].ask);
     }
 }  
 

Public Member Functions
	TYPE_DESCRIPTOR ((KEY(blockId, INDEXED), FIELD(used), FIELD(elements)))
Public Attributes
db_int4	used
db_int8	blockId
dbArray< T >	elements

---

Member Function Documentation

TYPE_DESCRIPTOR

(

(KEY(blockId, INDEXED), FIELD(used), FIELD(elements))

)

---

Member Data Documentation

db_int4 used

db_int8 blockId

dbArray<T> elements