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< p > Library Version 11.2.5.2< / p >
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< th colspan = "3" align = "center" > DbMultipleDataBuilder< / th >
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The Dbt Handle
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< h2 class = "title" style = "clear: both" > < a id = "dbmultipledatabuilder" > < / a > DbMultipleDataBuilder< / h2 >
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< pre class = "programlisting" > #include < db_cxx.h>
class DbMultipleDataBuilder
{
public:
DbMultipleDataBuilder(Dbt & dbt);
bool append(void *dbuf, size_t dlen);
bool reserve(void *& ddest, size_t dlen);
}; < / pre >
< p >
This class builds a bulk buffer for use when the
< a class = "link" href = "dbput.html#put_DB_MULTIPLE" > DB_MULTIPLE< / a >
flag is specified to either the
< a class = "xref" href = "dbput.html" title = "Db::put()" > Db::put()< / a > or
< a class = "xref" href = "dbdel.html" title = "Db::del()" > Db::del()< / a > methods. The buffer in
the < a class = "link" href = "dbt.html" title = "Chapter > Dbt< / a > passed to the constructor is
filled by calls to
< a class = "xref" href = "dbmultipledatabuilder.html#dbmultipledatabuilder.append" title = "DbMultipleDataBuilder.append()" > DbMultipleDataBuilder.append()< / a >
or
< a class = "xref" href = "dbmultipledatabuilder.html#dbmultipledatabuilder.reserve" title = "DbMultipleDataBuilder.reserve()" > DbMultipleDataBuilder.reserve()< / a > .
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< p >
The constructor takes a < a class = "xref" href = "dbt.html" title = "Chapter >
The Dbt Handle
< / a >
that must be configured to contain a buffer managed by the application,
with the < code class = "literal" > ulen< / code > field set to the size of the buffer.
< / p >
< div class = "note" style = "margin-left: 0.5in; margin-right: 0.5in;" >
< h3 class = "title" > Note< / h3 >
< p >
All instances of the bulk retrieval classes may be used only once,
and to build the bulk buffer in the forward direction only.
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< p >
Parameters are:
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< code class = "literal" > dbt< / code >
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< p >
The < span class = "bold" > < strong > dbt< / strong > < / span > parameter is a < a class = "xref" href = "dbt.html" title = "Chapter >
The Dbt Handle
< / a > that must already be configured to contain a buffer managed by the application, with the < code class = "literal" > ulen< / code > field set to the size of the buffer, which must be a multiple of 4.
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< h3 class = "title" > < a id = "dbmultipledatabuilder.append" > < / a > DbMultipleDataBuilder.append()< / h3 >
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< p >
The < code class = "methodname" > DbMultipleDataBuilder.append()< / code > method
copies a data item to the end of the buffer.
< / p >
< p >
The < code class = "methodname" > DbMultipleDataBuilder.append()< / code >
method returns < code class = "literal" > false< / code > if the data does not fit
in the buffer and < code class = "literal" > true< / code > otherwise.
< / p >
< p >
Parameters are:
< / p >
< div class = "itemizedlist" >
< ul type = "disc" >
< li >
< p >
< code class = "literal" > dbuf< / code >
< / p >
< p >
A pointer to the data to be copied into the bulk buffer.
< / p >
< / li >
< li >
< p >
< code class = "literal" > dlen< / code >
< / p >
< p >
The number of bytes to be copied.
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< h3 class = "title" > < a id = "dbmultipledatabuilder.reserve" > < / a > DbMultipleDataBuilder.reserve()< / h3 >
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< p >
The < code class = "methodname" > DbMultipleDataBuilder.reserve()< / code >
method reserves space for the next data item in the bulk buffer.
Unlike the < code class = "methodname" > append()< / code > , no data is actually
copied into the bulk buffer by < code class = "methodname" > reserve()< / code > :
copying the data is the responsibility of the application.
< / p >
< p >
The < code class = "methodname" > DbMultipleDataBuilder.reserve()< / code >
method returns < code class = "literal" > false< / code > if the data does
not fit in the buffer and < code class = "literal" > true< / code > otherwise.
< / p >
< p >
Parameters are:
< / p >
< div class = "itemizedlist" >
< ul type = "disc" >
< li >
< p >
< code class = "literal" > ddest< / code >
< / p >
< p >
Set to a pointer to the position in the bulk buffer reserved for the data item, if enough space is available.
< / p >
< / li >
< li >
< p >
< code class = "literal" > dlen< / code >
< / p >
< p >
The number of bytes to reserve.
< / p >
< / li >
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2011-12-20 00:07:10 +00:00
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< a class = "link" href = "dbt.html" title = "Chapter > Dbt< / a >
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< h3 class = "title" > < a id = "id3590916" > < / a > See Also< / h3 >
2011-09-13 17:44:24 +00:00
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