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upscaledb
2.2.1
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#include <upscaledb_uqi.h>
A plugin descriptor. Describes the implementation of a user-supplied aggregation or predicate function and can be loaded dynamically from an external library.
Plugins can be loaded dynamically from a library (.DLL/.SO etc) by specifying a function name in a query string, i.e.
foo@path/to/library.dll
or
The library name can be either an absolute path or a (relative) file name, in the latter case the system's library directories will be searched for the file. The library can be ommitted if the plugin was registered with uqi_register_plugin.
After the file is loaded, a function with the following interface is invoked:
uqi_plugin_t *plugin_descriptor(const char *name);
The parameter |name| is "foo" in our example. The function |plugin_descriptor| must be an exported symbol with the "C" calling convention.
Definition at line 219 of file upscaledb_uqi.h.
| uqi_plugin_aggregate_many_function uqi_plugin_t::agg_many |
The aggregation function; must be implemented if type is UQI_PLUGIN_AGGREGATE, otherwise set to null
Definition at line 256 of file upscaledb_uqi.h.
Referenced by main().
| uqi_plugin_aggregate_single_function uqi_plugin_t::agg_single |
The aggregation function; must be implemented if type is UQI_PLUGIN_AGGREGATE, otherwise set to null
Definition at line 250 of file upscaledb_uqi.h.
Referenced by main().
| uqi_plugin_cleanup_function uqi_plugin_t::cleanup |
The de-initialization function; can be null
Definition at line 244 of file upscaledb_uqi.h.
Referenced by main().
| uint32_t uqi_plugin_t::flags |
The plugin flags - either 0, or : if set, then key AND record stream will be passed to the predicate. Otherwise, the query engine will only pass keys (or records), not both.
Definition at line 235 of file upscaledb_uqi.h.
| uqi_plugin_init_function uqi_plugin_t::init |
The initialization function; can be null
Definition at line 241 of file upscaledb_uqi.h.
Referenced by main().
| const char* uqi_plugin_t::name |
| uint32_t uqi_plugin_t::plugin_version |
The version of the plugin's interface; always set to 0
Definition at line 238 of file upscaledb_uqi.h.
| uqi_plugin_predicate_function uqi_plugin_t::pred |
The predicate function; must be implemented if type is UQI_PLUGIN_PREDICATE, otherwise set to null
Definition at line 262 of file upscaledb_uqi.h.
Referenced by main().
| uqi_plugin_result_function uqi_plugin_t::results |
Assigns the result to a uqi_result_t structure; must not be null
Definition at line 265 of file upscaledb_uqi.h.
Referenced by main().
| uint32_t uqi_plugin_t::type |
The type of this plugin - either UQI_PLUGIN_PREDICATE or UQI_PLUGIN_AGGREGATE
Definition at line 227 of file upscaledb_uqi.h.
Referenced by main().
1.8.11