From 4faa0274aa25fba2b5ed0beb988ca48b2c24e86e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Wo=C5=9B?= <maciej.wos@gmail.com>
Date: Wed, 13 Sep 2023 15:01:23 +0200
Subject: [PATCH] handle missing blocks as a speacial case of database error

---
 packages/fuel-indexer-lib/src/lib.rs  |  5 +++++
 packages/fuel-indexer/src/executor.rs | 10 ++++++++++
 packages/fuel-indexer/src/ffi.rs      | 24 ++++++++++++++++++++++--
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/packages/fuel-indexer-lib/src/lib.rs b/packages/fuel-indexer-lib/src/lib.rs
index 1a26e983a..2d3d98727 100644
--- a/packages/fuel-indexer-lib/src/lib.rs
+++ b/packages/fuel-indexer-lib/src/lib.rs
@@ -46,6 +46,7 @@ pub enum WasmIndexerError {
     UnableToFetchLogString,
     KillSwitch,
     DatabaseError,
+    MissingBlocksError,
     GeneralError,
 }
 
@@ -60,6 +61,7 @@ impl From<u32> for WasmIndexerError {
             5 => Self::UnableToFetchLogString,
             6 => Self::KillSwitch,
             7 => Self::DatabaseError,
+            8 => Self::MissingBlocksError,
             _ => Self::GeneralError,
         }
     }
@@ -92,6 +94,9 @@ impl std::fmt::Display for WasmIndexerError {
             Self::DatabaseError => {
                 write!(f, "Failed performing a database operation")
             }
+            Self::MissingBlocksError => {
+                write!(f, "Some blocks are missing")
+            }
             Self::GeneralError => write!(f, "Some unspecified WASM error occurred."),
         }
     }
diff --git a/packages/fuel-indexer/src/executor.rs b/packages/fuel-indexer/src/executor.rs
index 24d3d9c88..2290b0320 100644
--- a/packages/fuel-indexer/src/executor.rs
+++ b/packages/fuel-indexer/src/executor.rs
@@ -190,6 +190,16 @@ pub fn run_executor<T: 'static + Executor + Send + Sync>(
             }
 
             if let Err(e) = result {
+                if let IndexerError::RuntimeError(ref e) = e {
+                    if let Some(&WasmIndexerError::MissingBlocksError) =
+                        e.downcast_ref::<WasmIndexerError>()
+                    {
+                        error!(
+                            "Indexer({indexer_uid}) terminating due to missing blocks."
+                        );
+                        break;
+                    }
+                }
                 // Run time metering is deterministic. There is no point in retrying.
                 if let IndexerError::RunTimeLimitExceededError = e {
                     error!("Indexer({indexer_uid}) executor run time limit exceeded. Giving up. <('.')>. Consider increasing metering points");
diff --git a/packages/fuel-indexer/src/ffi.rs b/packages/fuel-indexer/src/ffi.rs
index be4b763c7..7480c15b0 100644
--- a/packages/fuel-indexer/src/ffi.rs
+++ b/packages/fuel-indexer/src/ffi.rs
@@ -227,7 +227,7 @@ fn put_object(
 
     if let Err(e) = result {
         error!("Failed to put_object: {e}");
-        return Err(WasmIndexerError::DatabaseError);
+        return Err(database_operation_failure(e));
     };
 
     Ok(())
@@ -285,12 +285,32 @@ fn put_many_to_many_record(
 
     if let Err(e) = result {
         error!("Failed to put_many_to_many_record: {e:?}");
-        return Err(WasmIndexerError::DatabaseError);
+        return Err(database_operation_failure(e));
     }
 
     Ok(())
 }
 
+// Takes care of the exception raised by a trigger to ensure no blocks are
+// missed by the indexers.
+fn database_operation_failure(e: crate::IndexerError) -> WasmIndexerError {
+    match e {
+        crate::IndexerError::SqlxError(e) => {
+            if let Some(e) = e.as_database_error() {
+                if let Some(e) = e.try_downcast_ref::<sqlx::postgres::PgDatabaseError>() {
+                    if let Some(source) = e.r#where() {
+                        if source.contains("PL/pgSQL function ensure_block_height_consecutive() line 8 at RAISE") {
+                            return WasmIndexerError::MissingBlocksError
+                        }
+                    }
+                }
+            }
+            WasmIndexerError::DatabaseError
+        }
+        _ => WasmIndexerError::DatabaseError,
+    }
+}
+
 /// When called from WASM it will terminate the execution and return the error
 /// code.
 pub fn early_exit(err_code: u32) -> Result<(), WasmIndexerError> {