2011-09-13 17:44:24 +00:00
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< div class = "sect1" lang = "en" xml:lang = "en" > < div class = "titlepage" > < div > < div > < h2 class = "title" style = "clear: both" > < a id = "dbmultiplerecnodatabuilder" > < / a > DbMultipleRecnoDataBuilder< / h2 > < / div > < / div > < / div > < pre class = "programlisting" > #include < db_cxx.h>
class DbMultipleRecnoDataBuilder
{
public:
DbMultipleRecnoDataBuilder(Dbt & dbt);
bool append(db_recno_t recno, void *dbuf, size_t dlen);
bool reserve(db_recno_t recno, 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_KEY" > DB_MULTIPLE_KEY< / 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 with the recno
or queue access methods, or for the < code class = "literal" > key< / code > when the
< a class = "link" href = "dbput.html#put_DB_MULTIPLE" > DB_MULTIPLE< / a > flag is used. 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 = "dbmultiplerecnodatabuilder.html#dbmultiplerecnodatabuilder.append" title = "DbMultipleRecnoDataBuilder.append()" > DbMultipleRecnoDataBuilder.append()< / a >
or
< a class = "xref" href = "dbmultiplerecnodatabuilder.html#dbmultiplerecnodatabuilder.reserve" title = "DbMultipleRecnoDataBuilder.reserve()" > DbMultipleRecnoDataBuilder.reserve()< / a > .
< / p > < 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.
< / p > < / div > < p >
Parameters are:
< / p > < div class = "itemizedlist" > < ul type = "disc" > < li > < p >
< code class = "literal" > dbt< / code >
< / p > < 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.
< / p > < / li > < / ul > < / div >
bool append(db_recno_t recno, void *dbuf, size_t dlen);
< div class = "sect2" lang = "en" xml:lang = "en" > < div class = "titlepage" > < div > < div > < h3 class = "title" > < a id = "dbmultiplerecnodatabuilder.append" > < / a > DbMultipleRecnoDataBuilder.append()< / h3 > < / div > < / div > < / div > < p >
The < code class = "methodname" > DbMultipleRecnoDataBuilder.append()< / code >
method copies a record number / data pair to the end of the buffer.
< / p > < p >
The < code class = "methodname" > DbMultipleRecnoDataBuilder.append()< / code >
method returns < code class = "literal" > false< / code > if the record
number / data pair 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" > recno< / code >
< / p > < p >
The record number to append.
< / p > < / li > < li > < p >
< code class = "literal" > dbuf< / code >
< / p > < p >
A pointer to the data item to be copied into the bulk
buffer.
< / p > < / li > < li > < p >
< code class = "literal" > dlen< / code >
< / p > < p >
The number of bytes of the data item to be copied.
< / p > < / li > < / ul > < / div > < / div > < div class = "sect2" lang = "en" xml:lang = "en" > < div class = "titlepage" > < div > < div > < h3 class = "title" > < a id = "dbmultiplerecnodatabuilder.reserve" > < / a > DbMultipleRecnoDataBuilder.reserve()< / h3 > < / div > < / div > < / div > < p >
The < code class = "methodname" > DbMultipleRecnoDataBuilder.reserve()< / code >
method reserves space for the next record number / data pair in
the bulk buffer. The record number is appended, but unlike the
< code class = "methodname" > append()< / code > , the data is not 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" > DbMultipleRecnoDataBuilder.reserve()< / code >
method returns < code class = "literal" > false< / code > if the record 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" > recno< / code >
< / p > < p >
The record number to append.
< / p > < / li > < 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 for the data item.
2011-12-20 00:07:10 +00:00
< / p > < / li > < / ul > < / div > < / div > < div class = "sect2" lang = "en" xml:lang = "en" > < div class = "titlepage" > < div > < div > < h3 class = "title" > < a id = "id3591909" > < / a > Class< / h3 > < / div > < / div > < / div > < p >
2011-09-13 17:44:24 +00:00
< a class = "link" href = "dbmultiplebuilder.html" title = "DbMultipleBuilder" > DbMultipleBuilder< / a >
2011-12-20 00:07:10 +00:00
< / p > < / div > < div class = "sect2" lang = "en" xml:lang = "en" > < div class = "titlepage" > < div > < div > < h3 class = "title" > < a id = "id3592080" > < / a > See Also< / h3 > < / div > < / div > < / div > < p >
2011-09-13 17:44:24 +00:00
< a class = "xref" href = "dbt.html#dbtlist" title = "DBT and Bulk Operations" > DBT and Bulk Operations< / a >
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