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Telegram/Share/PSLMDBKeyValueCursor.m
2015-10-01 19:19:52 +03:00

138 lines
3.4 KiB
Objective-C

#import "PSLMDBKeyValueCursor.h"
#import "PSLMDBTable.h"
@interface PSLMDBKeyValueCursor ()
{
MDB_dbi _dbi;
MDB_txn *_txn;
MDB_cursor *_cursor;
}
@end
@implementation PSLMDBKeyValueCursor
- (instancetype)initWithTable:(PSLMDBTable *)table transaction:(MDB_txn *)transaction cursor:(MDB_cursor *)cursor
{
self = [super init];
if (self != nil)
{
_dbi = table.dbi;
_txn = transaction;
_cursor = cursor;
}
return self;
}
- (bool)positionAt:(uint8_t const **)key keyLength:(NSUInteger *)keyLength value:(uint8_t const **)value valueLength:(NSUInteger *)valueLength directionIfNotFound:(PSKeyValueCursorDirection)directionIfNotFound
{
if (key == NULL || keyLength == 0)
return false;
MDB_val mdbKey = {.mv_data = (void *)*key, .mv_size = *keyLength};
MDB_val mdbData = {.mv_data = NULL, .mv_size = 0};
int rc = 0;
rc = mdb_cursor_get(_cursor, &mdbKey, &mdbData, directionIfNotFound == PSKeyValueCursorDirectionForward ? MDB_SET_RANGE : MDB_SET_KEY);
if (rc == MDB_SUCCESS)
{
*key = mdbKey.mv_data;
*keyLength = mdbKey.mv_size;
if (value != NULL)
*value = mdbData.mv_data;
if (valueLength != NULL)
*valueLength = mdbData.mv_size;
return true;
}
else if (rc == MDB_NOTFOUND)
{
if (directionIfNotFound == PSKeyValueCursorDirectionBack)
return [self previous:key keyLength:keyLength value:value valueLength:valueLength];
}
else
{
NSLog(@"[PSLMDBKeyValueReader mdb_cursor_get error %d]", rc);
return false;
}
return false;
}
- (bool)previous:(uint8_t const **)key keyLength:(NSUInteger *)keyLength value:(uint8_t const **)value valueLength:(NSUInteger *)valueLength
{
if (key == NULL || keyLength == 0)
return false;
MDB_val mdbKey = {.mv_data = NULL, .mv_size = 0};
MDB_val mdbData = {.mv_data = NULL, .mv_size = 0};
int rc = 0;
rc = mdb_cursor_get(_cursor, &mdbKey, &mdbData, MDB_PREV);
if (rc == MDB_SUCCESS)
{
*key = mdbKey.mv_data;
*keyLength = mdbKey.mv_size;
if (value != NULL)
*value = mdbData.mv_data;
if (valueLength != NULL)
*valueLength = mdbData.mv_size;
return true;
}
else
{
if (rc != MDB_NOTFOUND)
NSLog(@"[PSLMDBKeyValueReader mdb_cursor_get error %d]", rc);
return false;
}
return false;
}
- (bool)next:(uint8_t const **)key keyLength:(NSUInteger *)keyLength value:(uint8_t const **)value valueLength:(NSUInteger *)valueLength
{
if (key == NULL || keyLength == 0)
return false;
MDB_val mdbKey = {.mv_data = NULL, .mv_size = 0};
MDB_val mdbData = {.mv_data = NULL, .mv_size = 0};
int rc = 0;
rc = mdb_cursor_get(_cursor, &mdbKey, &mdbData, MDB_NEXT);
if (rc == MDB_SUCCESS)
{
*key = mdbKey.mv_data;
*keyLength = mdbKey.mv_size;
if (value != NULL)
*value = mdbData.mv_data;
if (valueLength != NULL)
*valueLength = mdbData.mv_size;
return true;
}
else
{
if (rc != MDB_NOTFOUND)
NSLog(@"[PSLMDBKeyValueReader mdb_cursor_get error %d]", rc);
return false;
}
return false;
}
@end