[Cherrypick] Cache enablement check and dab-draft.schema.json changes (…

…#2033)

Cherry picks #2011 and #2012 to main

# 2012

## Why make this change?

- Ensure cache is used when enabled and add additional checks to make
this flow as expected.

## What is this change?

- Change cache check to ensure dbpolicies are NOT resolved for request
in order to use cache
- Add check to ensure entity cache is enabled.

# 2011

## Why this change?

This change follows up on
#1865, which adds caching
support.
VSCode suggesting the new `cache` properties were errors when included
in the config file. That is because the properties needed to be added to
the json schema.

Global `cache` property in the `runtime` section which adjacent to
`rest`, `graphql`, and `host`.

```json
{
  "runtime": {
    "cache": {
      "enabled": false,
      "ttl-seconds": 5
    }
  }
}
```

and per entity alongside `source`, `graphql`, `rest`, and `permissions`

```json
{
  "myEntity": {
    "cache": {
      "enabled": false,
      "ttl-seconds": 5
    }
  }
}
```

---------

Co-authored-by: Aniruddh Munde <anmunde@microsoft.com>

schemas/dab.draft.schema.json

@@ -237,6 +237,22 @@
             }
           }
         },
+        "cache": {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "enabled": {
+              "type": "boolean",
+              "description": "Enable caching of responses globally.",
+              "default": false
+            },
+            "ttl-seconds": {
+              "type": "integer",
+              "description": "Time to live in seconds",
+              "default": 5
+            }
+          }
+        },
         "telemetry": {
           "type": "object",
           "description": "Telemetry configuration",
@@ -493,6 +509,22 @@
                   ]
                 }
               }
+            },
+            "cache": {
+              "type": "object",
+              "additionalProperties": false,
+              "properties": {
+                "enabled": {
+                  "type": "boolean",
+                  "description": "Enable caching of responses for this entity.",
+                  "default": false
+                },
+                "ttl-seconds": {
+                  "type": "integer",
+                  "description": "Time to live in seconds",
+                  "default": 5
+                }
+              }
             }
           },
           "if": {

src/Core/Resolvers/SqlQueryEngine.cs

@@ -211,11 +211,16 @@ public async Task<IActionResult> ExecuteAsync(StoredProcedureRequestContext cont
             // Open connection and execute query using _queryExecutor
             string queryString = queryBuilder.Build(structure);
 
+            // Global Cache enablement check
             if (runtimeConfig.CanUseCache())
             {
+                // Entity level cache behavior checks
                 bool dbPolicyConfigured = !string.IsNullOrEmpty(structure.DbPolicyPredicatesForOperations[EntityActionOperation.Read]);
+                bool entityCacheEnabled = runtimeConfig.Entities[structure.EntityName].IsCachingEnabled;
 
-                if (dbPolicyConfigured)
+                // If a db policy is configured for the read operation in the context of the executing role, skip the cache.
+                // We want to avoid caching token metadata because token metadata can change frequently and we want to avoid caching it.
+                if (!dbPolicyConfigured && entityCacheEnabled)
                 {
                     DatabaseQueryMetadata queryMetadata = new(queryText: queryString, dataSource: dataSourceName, queryParameters: structure.Parameters);
                     JsonElement result = await _cache.GetOrSetAsync<JsonElement>(queryExecutor, queryMetadata, cacheEntryTtl: runtimeConfig.GetEntityCacheEntryTtl(entityName: structure.EntityName));
@@ -225,6 +230,11 @@ public async Task<IActionResult> ExecuteAsync(StoredProcedureRequestContext cont
                 }
             }
 
+            // Execute a request normally (skipping cache) when any of the cache usage checks fail:
+            // 1. Global cache is disabled
+            // 2. MSSQL datasource set-session-context property is true
+            // 3. Entity level cache is disabled
+            // 4. A db policy is resolved for the read operation
             JsonDocument? response = await queryExecutor.ExecuteQueryAsync(
                 sqltext: queryString,
                 parameters: structure.Parameters,