implemented different types of pagination

CHANGELOG-UNRELEASED.md

@@ -7,7 +7,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 
 ### Changed
-
+- Changed Pagination to have different types [#2110](https://github.com/holochain/holochain-rust/pull/2110)
 ### Deprecated
 
 ### Removed

app_spec/test/files/links.js

@@ -1,4 +1,5 @@
 const { one, two } = require('../config')
+const sleep = require('sleep')
 
 module.exports = scenario => {
   scenario('delete_post', async (s, t) => {
@@ -132,6 +133,40 @@ module.exports = scenario => {
 
       t.equal(1, bob_posts_live_2.Ok.links.length)
       t.equal(1, alice_posts_live_2.Ok.links.length)
+      sleep.sleep(5);
+      const bob_posts_live_time = await bob.call('app', 'simple', 'get_my_links_with_time_pagination',
+      {
+        base: alice.info('app').agentAddress,
+        from_seconds: Math.floor(new Date() / 1000),//last ever second
+        limit:3
+      })
+
+      const alice_posts_live_time = await bob.call('app', 'simple', 'get_my_links_with_time_pagination',
+      {
+        base: alice.info('app').agentAddress,
+        from_seconds: Math.floor(new Date() / 1000),//last ever second
+        limit:3
+      })
+
+      t.equal(0, bob_posts_live_time.Ok.links.length)
+      t.equal(0, alice_posts_live_time.Ok.links.length)
+
+      const bob_posts_time_2 = await bob.call('app', 'simple', 'get_my_links_with_time_pagination',
+      {
+        base: alice.info('app').agentAddress,
+        from_seconds: 0,//first ever second
+        limit:3
+      })
+
+      const alice_posts_time_2 = await bob.call('app', 'simple', 'get_my_links_with_time_pagination',
+      {
+        base: alice.info('app').agentAddress,
+        from_seconds: 0,//first ever second
+        limit:3
+      })
+
+      t.equal(3, bob_posts_time_2.Ok.links.length)
+      t.equal(3, alice_posts_time_2.Ok.links.length)
   })
 
   scenario('get_links_crud', async (s, t) => {

app_spec/zomes/simple/code/src/lib.rs

@@ -73,7 +73,16 @@ pub fn handle_get_my_links_with_tag(agent : Address,status_request:LinksStatusRe
 pub fn handle_get_my_links_with_pagination(agent : Address,pagesize:usize,pagenumber:usize) ->ZomeApiResult<GetLinksResult>
 {
     let options = GetLinksOptions{
-        pagination : Some(Pagination{page_size : pagesize,page_number : pagenumber}),
+        pagination : Some(Pagination::Size(SizePagination{page_size : pagesize,page_number : pagenumber})),
+        ..GetLinksOptions::default()
+    };
+    hdk::get_links_with_options(&agent, LinkMatch::Exactly("authored_simple_posts"), LinkMatch::Any,options)
+}
+
+pub fn handle_get_my_links_with_time_pagination(agent : Address,from_seconds:i64,limit:usize) ->ZomeApiResult<GetLinksResult>
+{
+    let options = GetLinksOptions{
+        pagination : Some(Pagination::Time(TimePagination{from_time : Iso8601::new(from_seconds,0),limit})),
         ..GetLinksOptions::default()
     };
     hdk::get_links_with_options(&agent, LinkMatch::Exactly("authored_simple_posts"), LinkMatch::Any,options)
@@ -208,6 +217,11 @@ define_zome! {
             outputs: |result: ZomeApiResult<GetLinksResult>|,
             handler: handle_get_my_links_with_pagination
         }
+        get_my_links_with_time_pagination: {
+            inputs: |base: Address,from_seconds:i64,limit:usize|,
+            outputs: |result: ZomeApiResult<GetLinksResult>|,
+            handler: handle_get_my_links_with_time_pagination
+        }
         get_my_links_count: {
             inputs: |base: Address,status_request:LinksStatusRequestKind,tag:String|,
             outputs: |result: ZomeApiResult<GetLinksResultCount>|,
@@ -231,6 +245,6 @@ define_zome! {
     ]
 
     traits: {
-        hc_public [create_anchor, get_entry, create_link, delete_link, get_my_links, test_emit_signal,get_my_links_count,create_link_with_tag,get_my_links_count_by_tag,delete_link_with_tag,get_my_links_with_tag,encrypt,decrypt,get_my_links_with_pagination]
+        hc_public [create_anchor, get_entry, create_link, delete_link, get_my_links, test_emit_signal,get_my_links_count,create_link_with_tag,get_my_links_count_by_tag,delete_link_with_tag,get_my_links_with_tag,encrypt,decrypt,get_my_links_with_pagination,get_my_links_with_time_pagination]
     }
 }

crates/core/src/agent/state.rs

@@ -236,7 +236,7 @@ pub fn create_entry_with_header_for_header(
     root_state: &StateWrapper,
     chain_header: ChainHeader,
 ) -> Result<EntryWithHeader, HolochainError> {
-    let timestamp = chain_header.timestamp().clone();
+    let timestamp = *chain_header.timestamp();
     let entry = Entry::ChainHeader(chain_header);
     // This header entry needs its own header so we can publish it.
     // This is a bit delicate:

crates/core/src/dht/dht_store.rs

@@ -14,7 +14,7 @@ use holochain_core_types::{
     error::{HcResult, HolochainError},
     network::{
         entry_aspect::EntryAspect,
-        query::{GetLinksQueryConfiguration, SortOrder},
+        query::{GetLinksQueryConfiguration, Pagination, SortOrder},
     },
 };
 use holochain_json_api::{error::JsonError, json::JsonString};
@@ -29,6 +29,7 @@ use holochain_persistence_api::{
 use regex::Regex;
 
 use crate::{dht::pending_validations::PendingValidation, state::StateWrapper};
+use chrono::{offset::FixedOffset, DateTime};
 use holochain_json_api::error::JsonResult;
 use holochain_persistence_api::error::PersistenceResult;
 use std::{
@@ -176,18 +177,31 @@ impl DhtStore {
                 SortOrder::Ascending => Box::new(filtered.into_iter()),
                 SortOrder::Descending => Box::new(filtered.into_iter().rev()),
             };
-        Ok(filter_with_sort_order
-            .skip(
-                pagination
-                    .clone()
-                    .map(|page| page.page_size * page.page_number)
-                    .unwrap_or(0),
-            )
-            .take(
-                pagination
-                    .map(|page| page.page_size)
-                    .unwrap_or(std::usize::MAX),
-            )
+        let filter_with_pagination: Box<dyn Iterator<Item = EntityAttributeValueIndex>> =
+            match pagination {
+                Some(paginate) => match paginate {
+                    Pagination::Time(time_pagination) => {
+                        let paginated_time = time_pagination.clone();
+                        Box::new(
+                            filter_with_sort_order
+                                .skip_while(move |eavi| {
+                                    let from_time: DateTime<FixedOffset> =
+                                        paginated_time.from_time.into();
+                                    from_time.timestamp_nanos() >= eavi.index()
+                                })
+                                .take(time_pagination.limit),
+                        )
+                    }
+                    Pagination::Size(size_pagination) => Box::new(
+                        filter_with_sort_order
+                            .skip(size_pagination.page_size * size_pagination.page_number)
+                            .take(size_pagination.page_size),
+                    ),
+                },
+                None => filter_with_sort_order,
+            };
+
+        Ok(filter_with_pagination
             .map(|s| match s.attribute() {
                 Attribute::LinkTag(_, _) => (s, CrudStatus::Live),
                 _ => (s, CrudStatus::Deleted),

crates/core_types/src/network/query.rs

@@ -1,4 +1,7 @@
-use crate::{chain_header::ChainHeader, crud_status::CrudStatus, entry::EntryWithMetaAndHeader};
+use crate::{
+    chain_header::ChainHeader, crud_status::CrudStatus, entry::EntryWithMetaAndHeader,
+    time::Iso8601,
+};
 use holochain_json_api::{error::JsonError, json::JsonString};
 use holochain_persistence_api::{cas::content::Address, eav::Value};
 
@@ -16,11 +19,21 @@ impl Default for SortOrder {
     }
 }
 
+#[derive(Deserialize, Debug, Serialize, Clone, PartialEq, Eq, Hash, DefaultJson)]
+pub struct TimePagination {
+    pub from_time: Iso8601,
+    pub limit: usize,
+}
 #[derive(Deserialize, Default, Debug, Serialize, Clone, PartialEq, Eq, Hash, DefaultJson)]
-pub struct Pagination {
+pub struct SizePagination {
     pub page_number: usize,
     pub page_size: usize,
 }
+#[derive(Deserialize, Debug, Serialize, Clone, PartialEq, Eq, Hash, DefaultJson)]
+pub enum Pagination {
+    Size(SizePagination),
+    Time(TimePagination),
+}
 
 #[derive(Debug, Serialize, Deserialize, PartialEq, DefaultJson, Clone, Default)]
 pub struct GetLinksQueryConfiguration {

crates/core_types/src/time.rs

@@ -394,7 +394,7 @@ impl From<&Duration> for Period {
 ///    Debug:   Iso8601(2018-10-11T03:23:38+00:00)
 ///
 /// More info on the relevant [wikipedia article](https://en.wikipedia.org/wiki/ISO_8601).
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, DefaultJson)]
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, DefaultJson, Copy)]
 pub struct Iso8601(DateTime<FixedOffset>);
 
 /// Infallible conversions into and from an Iso8601.  The only infallible ways to create an Iso8601

crates/hdk/src/prelude.rs

@@ -19,7 +19,8 @@ pub use crate::{
         entry::{entry_type::EntryType, Entry},
         error::HolochainError,
         link::LinkMatch,
-        network::query::{Pagination, SortOrder},
+        network::query::{Pagination, SizePagination, SortOrder, TimePagination},
+        time::Iso8601,
     },
     holochain_json_api::{error::JsonError, json::JsonString},
     holochain_persistence_api::cas::content::{Address, AddressableContent},

doc/holochain_101/src/links/get_links.md

@@ -10,9 +10,8 @@ Get Links allows the zome developer to query links from the DHT. The call accept
 `Timeout` : The timeout variable on the options specifies how long the query process should wait befor a response before it timesout
 `LinksStatusRequest` : This is a variable in which you can specify 3 modes, `All`,`Live`,`Delete`. This allows you to query the links based on crud_status in which `All` will return everything will `Live` will only return live links and `Delete` as such.
 `Headers`: boolean value which if set to true indicates that the link headers should also be returned.```
-`Pagination`: The pagination type has two variables which are page size and page number. These describe the page size which divides the links into pages and the page number
-which describes the page that we want to get.
-'Sort Order' : Allows get_links to define which order `Ascending` or `Descending` the links should be returned in
+`Pagination`: The pagination type has two variants which are `Size` and `Time` These variants allow the user to paginate based on choosing pages and specifying page size, or by specifying a point time and specifying a limit of the number of entries (based on the timestamp in the entry header) to return from that point.
+`Sort Order` : Allows get_links to define which order `Ascending` or `Descending` the links should be returned in
 
 # Link Results