schema and changelog

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 # UNRELEASED
 
+### feat: `dfx canister [create|update-settings] --wasm-memory-threshold`
+
+This adds support for the WASM memory threshold, used in conjunction with `--wasm-memory-limit`.
+When the remaining memory until the limit falls below the threshold, the canister's
+`on_low_wasm_memory` handler is run.
+
 ### fix: `dfx deploy --by-proposal` no longer sends chunk data in ProposeCommitBatch
 
 Recently we made `dfx deploy` include some chunk data in CommitBatch, in order to streamline

docs/dfx-json-schema.json

@@ -447,7 +447,8 @@
             "log_visibility": null,
             "memory_allocation": null,
             "reserved_cycles_limit": null,
-            "wasm_memory_limit": null
+            "wasm_memory_limit": null,
+            "wasm_memory_threshold": null
           },
           "allOf": [
             {
@@ -1020,6 +1021,19 @@
               "type": "null"
             }
           ]
+        },
+        "wasm_memory_threshold": {
+          "title": "Wasm Memory Threshold",
+          "description": "Specifies a threshold (in bytes) on the Wasm memory usage of the canister, as a distance from `wasm_memory_limit`.\n\nWhen the remaining memory before the limit drops below this threshold, its `on_low_wasm_memory` hook will be invoked. This enables it to self-optimize, or raise an alert, or otherwise attempt to prevent itself from reaching `wasm_memory_limit`.\n\nMust be a number of bytes between 0 and 2^48 (i.e. 256 TiB), inclusive. Can be specified as an integer, or as an SI unit string (e.g. \"4KB\", \"2 MiB\")",
+          "default": null,
+          "anyOf": [
+            {
+              "$ref": "#/definitions/Byte"
+            },
+            {
+              "type": "null"
+            }
+          ]
         }
       }
     },