cpython-source-deps/docs_src/db/dbt_bulk_class.so

m4_comment([$Id: dbt_bulk_class.so,v 1.15 2004/08/13 03:38:56 bostic Exp $])

define(M4PAGELOCAL,
	[DbMultipleDataIterator, DbMultipleKeyDataIterator,
	DbMultipleRecnoDataIterator])
include(m4/m4.seealso)

m4_pf_header(Bulk Retrieval API,
ifelse(M4API, C_API, [dnl
])
ifelse(M4API, CXX_API, [dnl
class DbMultipleDataIterator
{
public:
	DbMultipleDataIterator(const Dbt &dbt);
m4_blank
	bool next(Dbt &data);
};
m4_blank
class DbMultipleKeyDataIterator
{
public:
	DbMultipleKeyDataIterator(const Dbt &dbt);
m4_blank
	bool next(Dbt &key, Dbt &data);
};
m4_blank
class DbMultipleRecnoDataIterator
{
public:
	DbMultipleRecnoDataIterator(const Dbt &dbt);
m4_blank
	bool next(db_recno_t &key, Dbt &data);
};
]))

m4_p([dnl
If either of the m4_ref(DB_MULTIPLE) or m4_ref(DB_MULTIPLE_KEY) flags
were specified to the m4_ref(dbh_get) or m4_refT(dbc_get), the data
m4_ref(Dbt) returned by those interfaces will refer to a buffer that
is filled with data.  Access to that data is through the following
classes.])

m4_p([dnl
All instances of the bulk retrieval classes may be used only once, and
to traverse the bulk retrieval buffer in the forward direction only.
However, they are nondestructive, so multiple iterators can be
instantiated and used on the same returned data m4_ref(Dbt).])

m4_pf_description(DbMultipleIterator)
m4_p([dnl
The m4_ref(DbMultipleIterator) is a shared package-private base class
for the three types of bulk-return Iterator; it should never be
instantiated directly, but it handles the functionality shared by its
subclasses.])

m4_pf_description(DbMultipleDataIterator)
m4_p([dnl
The m4_ref(DbMultipleDataIterator) class is used to iterate through data
returned using the m4_ref(DB_MULTIPLE) flag from a database belonging
to any access method.])

m4_p([dnl
The constructor takes the data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE)
flag.])
m4_parambegin
m4_param(dbt, [dnl
The m4_arg(dbt) parameter is a data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE)
flag.])
m4_paramend

m4_pf_description(DbMultipleDataIterator.next)
m4_p([dnl
The DbMultipleDataIterator.next method takes a m4_ref(Dbt) that will be
filled in with a reference to a buffer, a size, and an offset that
together yield the next data item in the original bulk retrieval buffer.])
m4_p([dnl
The DbMultipleDataIterator.next method returns false if no more data are
available, and true otherwise.])
m4_parambegin
m4_param(data, [dnl
The m4_arg(data) parameter is a m4_ref(Dbt) that will be filled in with
a reference to a buffer, a size, and an offset that together yield the
next data item in the original bulk retrieval buffer.])
m4_paramend

m4_pf_description(DbMultipleKeyDataIterator)
m4_p([dnl
The m4_ref(DbMultipleKeyDataIterator) class is used to iterate through
data returned using the m4_ref(DB_MULTIPLE_KEY) flag from a database
belonging to the Btree or Hash access methods.])

m4_p([dnl
The constructor takes the data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE_KEY)
flag.])
m4_parambegin
m4_param(dbt, [dnl
The m4_arg(dbt) parameter is a data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE_KEY)
flag.])
m4_paramend

m4_pf_description(DbMultipleKeyDataIterator.next)
m4_p([dnl
The DbMultipleKeyDataIterator.next method takes two m4_ref(Dbt)s, one
for a key and one for a data item, that will each be filled in with a
reference to a buffer, a size, and an offset that together yield the
next key and data item in the original bulk retrieval buffer.  The
DbMultipleKeyDataIterator.next method returns false if no more data are
available, and true otherwise.])
m4_p([dnl
The DbMultipleKeyDataIterator.next method returns false if no more data
are available, and true otherwise.])
m4_parambegin
m4_param(key, [dnl
The m4_arg(key) parameter will be filled in with a reference to a buffer,
a size, and an offset that yields the next key item in the original bulk
retrieval buffer.])
m4_param(data, [dnl
The m4_arg(data) parameter will be filled in with a reference to a buffer,
a size, and an offset that yields the next data item in the original bulk
retrieval buffer.])
m4_paramend

m4_pf_description(DbMultipleRecnoDataIterator)
m4_p([dnl
This class is used to iterate through data returned using the
m4_ref(DB_MULTIPLE_KEY) flag from a database belonging to the Recno or
Queue access methods.])

m4_p([dnl
The constructor takes the data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE_KEY)
flag.])
m4_parambegin
m4_param(dbt, [dnl
The m4_arg(dbt) parameter is a data m4_ref(Dbt) returned by the call to
m4_ref(dbh_get) or m4_ref(dbc_get) that used the m4_ref(DB_MULTIPLE_KEY)
flag.])
m4_paramend

m4_pf_description(DbMultipleRecnoDataIterator.next)
ifelse(M4API, CXX_API, [dnl
The DbMultipleRecnoDataIterator.next method takes a m4_arg(db_recno_t)
for the key and a m4_ref(Dbt) for a data item, which will be filled in
with a pointer to a buffer and a size.  Together they yield the next key
and data item in the original bulk retrieval buffer.])
m4_p([dnl
The DbMultipleRecnoDataIterator.next method returns false if no more
data are available, and true otherwise.])
m4_parambegin
m4_param(key, [dnl
The m4_arg(key) parameter will be filled in with a reference to a
buffer, a size, and an offset that yields the next key item in the
original bulk retrieval buffer.])
m4_param(data, [dnl
The m4_arg(data) parameter will be filled in with a reference to a
buffer, a size, and an offset that yields the next data item in the
original bulk retrieval buffer.])
m4_paramend

m4_page_footer