Re: [ApacheDS] how can a partition return more than one result ?
Von meinem iPad gesendet But I am only able to return ONE entry, I didn't find or understand the concept how MULTIPLE entries can be returned. Can someone show me the right direction ? The idea is to use a Cursor that maps around the partition and fetch the entries one by one. The way the server works is that based on your filter, you select the right index to use to fetch the entries. There are may possibilities here : - first, you may have to do a full scan (the filter is not selective enough, for instance). In this case, you don't use any index, you just use the MasterTable to get the entries. Now, for each entry you fetch, you'll have to filter them to see if it's a valid entry - or not. - or you can select an index. You will fetch the index elements, and for each of them, fetch the associated entry. Once done, you can check against the filter if the entry is valid - or not In any case, the cursor is your friend here : it maps the next() operation on top of your index. Now, if your Partition is a Btree, it's easier, as the AbstractBTreePartition class already handles everyting for you. If you don't inherit from this Abstract class, then it's way more complicated. I'll suggest you have a look at the AbstractBTreePartition to get a clue about how we process a search over a BTree based partition. If I got you right I am to create my own cursor object which retrieves and stores the array with the items I want to deliver. The cursor then implements the next and get method in order to send the array one by one. But where is the cursor being called ? I tried to base my own partition on the abstract btree partition but what am I supposed to return from getRootId and getDefaultId and even worse from convertAndInit ? Sorry for the beginner level questions but ApacheDS is quite complex and new to me.
[ApacheDS] how can a partition return more than one result ?
I learned a lot about the implementation of custom partitions and see the changes in the API from search and lookup returning an Entry in 1.5.x and an EntryFilteringCursor later on. I even was able to change an existing partition (shame on me: based on the 1.5.5 example, but I will switch to 2.0 soon) in a way that lets it return a fake group object that was created in my custom POJO. But I am only able to return ONE entry, I didn't find or understand the concept how MULTIPLE entries can be returned. Can someone show me the right direction ?
Re: [ApacheDS] how can a partition return more than one result ?
Le 6/8/12 1:49 PM, Garbage a écrit : I learned a lot about the implementation of custom partitions and see the changes in the API from search and lookup returning an Entry in 1.5.x and an EntryFilteringCursor later on. I even was able to change an existing partition (shame on me: based on the 1.5.5 example, but I will switch to 2.0 soon) in a way that lets it return a fake group object that was created in my custom POJO. But I am only able to return ONE entry, I didn't find or understand the concept how MULTIPLE entries can be returned. Can someone show me the right direction ? The idea is to use a Cursor that maps around the partition and fetch the entries one by one. The way the server works is that based on your filter, you select the right index to use to fetch the entries. There are may possibilities here : - first, you may have to do a full scan (the filter is not selective enough, for instance). In this case, you don't use any index, you just use the MasterTable to get the entries. Now, for each entry you fetch, you'll have to filter them to see if it's a valid entry - or not. - or you can select an index. You will fetch the index elements, and for each of them, fetch the associated entry. Once done, you can check against the filter if the entry is valid - or not In any case, the cursor is your friend here : it maps the next() operation on top of your index. Now, if your Partition is a Btree, it's easier, as the AbstractBTreePartition class already handles everyting for you. If you don't inherit from this Abstract class, then it's way more complicated. I'll suggest you have a look at the AbstractBTreePartition to get a clue about how we process a search over a BTree based partition. -- Regards, Cordialement, Emmanuel Lécharny www.iktek.com
Re: [ApacheDS] how can a partition return more than one result ?
Am 08.06.2012 um 13:58 schrieb Emmanuel Lécharny elecha...@gmail.com: Le 6/8/12 1:49 PM, Garbage a écrit : I learned a lot about the implementation of custom partitions and see the changes in the API from search and lookup returning an Entry in 1.5.x and an EntryFilteringCursor later on. I even was able to change an existing partition (shame on me: based on the 1.5.5 example, but I will switch to 2.0 soon) in a way that lets it return a fake group object that was created in my custom POJO. But I am only able to return ONE entry, I didn't find or understand the concept how MULTIPLE entries can be returned. Can someone show me the right direction ? The idea is to use a Cursor that maps around the partition and fetch the entries one by one. The way the server works is that based on your filter, you select the right index to use to fetch the entries. There are may possibilities here : - first, you may have to do a full scan (the filter is not selective enough, for instance). In this case, you don't use any index, you just use the MasterTable to get the entries. Now, for each entry you fetch, you'll have to filter them to see if it's a valid entry - or not. - or you can select an index. You will fetch the index elements, and for each of them, fetch the associated entry. Once done, you can check against the filter if the entry is valid - or not In any case, the cursor is your friend here : it maps the next() operation on top of your index. Now, if your Partition is a Btree, it's easier, as the AbstractBTreePartition class already handles everyting for you. If you don't inherit from this Abstract class, then it's way more complicated. I'll suggest you have a look at the AbstractBTreePartition to get a clue about how we process a search over a BTree based partition. -- Regards, Cordialement, Emmanuel Lécharny www.iktek.com Thanks, I will investigate this. What a pity, I am able to map searches to string arrays containing the name of groups I want to return. But I understand why you don't support arrays directly, I will somehow manage to map to the Bree example. And if not I will show up here again ;-)
Re: [ApacheDS] how can a partition return more than one result ?
Le 6/8/12 2:05 PM, Garbage a écrit : Am 08.06.2012 um 13:58 schrieb Emmanuel Lécharnyelecha...@gmail.com: Le 6/8/12 1:49 PM, Garbage a écrit : I learned a lot about the implementation of custom partitions and see the changes in the API from search and lookup returning an Entry in 1.5.x and an EntryFilteringCursor later on. I even was able to change an existing partition (shame on me: based on the 1.5.5 example, but I will switch to 2.0 soon) in a way that lets it return a fake group object that was created in my custom POJO. But I am only able to return ONE entry, I didn't find or understand the concept how MULTIPLE entries can be returned. Can someone show me the right direction ? The idea is to use a Cursor that maps around the partition and fetch the entries one by one. The way the server works is that based on your filter, you select the right index to use to fetch the entries. There are may possibilities here : - first, you may have to do a full scan (the filter is not selective enough, for instance). In this case, you don't use any index, you just use the MasterTable to get the entries. Now, for each entry you fetch, you'll have to filter them to see if it's a valid entry - or not. - or you can select an index. You will fetch the index elements, and for each of them, fetch the associated entry. Once done, you can check against the filter if the entry is valid - or not In any case, the cursor is your friend here : it maps the next() operation on top of your index. Now, if your Partition is a Btree, it's easier, as the AbstractBTreePartition class already handles everyting for you. If you don't inherit from this Abstract class, then it's way more complicated. I'll suggest you have a look at the AbstractBTreePartition to get a clue about how we process a search over a BTree based partition. -- Regards, Cordialement, Emmanuel Lécharny www.iktek.com Thanks, I will investigate this. What a pity, I am able to map searches to string arrays containing the name of groups I want to return. But I understand why you don't support arrays directly, I will somehow manage to map to the Bree example. And if not I will show up here again ;-) If you already have an array, you just have to create your own cursor wraping it, maintaining the current index, and the next() call will simply fetch the next entry in the arry, incrementing the pointer. This is pretty simple to implement, I think. -- Regards, Cordialement, Emmanuel Lécharny www.iktek.com
