From 640f720fad6de43b24e4f6e542de4d3d07049163 Mon Sep 17 00:00:00 2001
From: Jesse Eisses <jesse.eisses@gmail.com>
Date: Sun, 8 Jan 2023 15:17:36 +0100
Subject: [PATCH] force: Add `cleartasks` action to clear RAM for expired tasks

Submissions can be deleted if the batch has been deleted. This code
still needs testing. See issue #94.
---
 contracts/force/force.cpp | 23 +++++++++++++++++++++++
 contracts/force/force.hpp | 21 +++++++++++++++------
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/contracts/force/force.cpp b/contracts/force/force.cpp
index 73f7db1..7ec35e9 100644
--- a/contracts/force/force.cpp
+++ b/contracts/force/force.cpp
@@ -96,6 +96,7 @@ void force::rmbatch(uint32_t id, uint32_t campaign_id, vaccount::sig sig) {
   uint64_t batch_pk =(uint64_t{campaign_id} << 32) | id;
 
   auto& camp = camp_tbl.get(campaign_id, "campaign not found");
+
   auto batch_itr = batch_tbl.find(batch_pk);
   eosio::check(batch_itr != batch_tbl.end(), "batch does not exist");
 
@@ -108,6 +109,28 @@ void force::rmbatch(uint32_t id, uint32_t campaign_id, vaccount::sig sig) {
   batch_tbl.erase(batch_itr);
 }
 
+void force::cleartasks(uint64_t batch_pk, vaccount::sig sig) {
+  // tasks can only be cleared if the batch is removed
+  batch_table batch_tbl(_self, _self.value);
+  auto batch_itr = batch_tbl.find(batch_pk);
+  eosio::check(batch_itr == batch_tbl.end(), "batch still exists");
+
+  // remove the submissoins in this batch
+  submission_table submission_tbl(_self, _self.value);
+  auto by_batch = submission_tbl.get_index<"batch"_n>();
+  auto itr_start = by_batch.lower_bound(batch_pk);
+  auto itr_end = by_batch.upper_bound(batch_pk);
+  int erased = 0;
+
+  for (; itr_start != itr_end; itr_start++) {
+    erased++;
+    auto& subm = *itr_start;
+    submission_tbl.erase(subm);
+    if (erased >= 100)
+      break;
+  }
+}
+
 void force::publishbatch(uint64_t batch_id, uint32_t num_tasks, vaccount::sig sig) {
   batch_table batch_tbl(_self, _self.value);
   auto& batch = batch_tbl.get(batch_id, "batch not found");
diff --git a/contracts/force/force.hpp b/contracts/force/force.hpp
index 3fb1be3..335118b 100644
--- a/contracts/force/force.hpp
+++ b/contracts/force/force.hpp
@@ -94,6 +94,10 @@ class [[eosio::contract("force")]] force : public eosio::contract {
                uint32_t campaign_id,
                vaccount::sig sig);
 
+  [[eosio::action]]
+  void cleartasks(uint64_t batch_pk,
+                  vaccount::sig sig);
+
   [[eosio::action]]
   void closebatch(uint64_t batch_id,
                   vaccount::vaddress owner,
@@ -425,12 +429,17 @@ class [[eosio::contract("force")]] force : public eosio::contract {
 
   typedef multi_index<"campaign"_n, campaign> campaign_table;
   typedef multi_index<"batch"_n, batch> batch_table;
-  typedef multi_index<"batchjoin"_n, batchjoin,
-                      indexed_by<"accbatch"_n, const_mem_fun<batchjoin, uint128_t, &batchjoin::by_account_batch>>> batchjoin_table;
-
-  typedef multi_index<"submission"_n, submission,
-                      indexed_by<"leaf"_n, const_mem_fun<submission, checksum256, &submission::by_leaf>>,
-                      indexed_by<"batch"_n, const_mem_fun<submission, uint64_t, &submission::by_batch>>>
+  typedef multi_index<
+    "batchjoin"_n,
+    batchjoin,
+    indexed_by<"accbatch"_n,
+               const_mem_fun<batchjoin, uint128_t, &batchjoin::by_account_batch>>>
+  batchjoin_table;
+
+  typedef multi_index<
+    "submission"_n, submission,
+    indexed_by<"leaf"_n, const_mem_fun<submission, checksum256, &submission::by_leaf>>,
+    indexed_by<"batch"_n, const_mem_fun<submission, uint64_t, &submission::by_batch>>>
   submission_table;
 
   typedef multi_index<"payment"_n, payment,