Take messages of number and text fields, several variable ones, as JSON

A message field is now a u32, a number (binary64), bytes or text, and
variable fields may be several and anywhere: the payload's prefix holds
the fixed fields and each variable field's length but the last one's,
which takes the rest; a module whose one bytes field came last is laid
out as before. On arrival a length past the payload, a text that is not
UTF-8 or a number that is not finite fails the message.

pure-serve fills an input's message from a JSON object body
(Content-Type: application/json) on the connection thread before the
request is ready, so the owner never parses and replies are still
borrowed: the ingress is [u32 payload size][payload][the JSON as it
came]. A missing, unknown, doubled or mistyped field, or text that is not
JSON, answers 400 and the request never runs. Numbers may come in the
query too.

1 files changed, 8 insertions, 1 deletions

diff --git a/prototypes/connections/module.h b/prototypes/connections/module.h
index 09a8540..52671f0 100644
--- a/prototypes/connections/module.h
+++ b/prototypes/connections/module.h
@@ -51,7 +51,14 @@ typedef enum { PURE_FOLD_COUNT, PURE_FOLD_SUM, PURE_FOLD_MAX, PURE_FOLD_MIN, PUR
 typedef enum { PURE_LESS, PURE_LESS_EQUAL, PURE_GREATER, PURE_GREATER_EQUAL, PURE_EQUAL, PURE_NOT_EQUAL } PureRelation;
 
 typedef enum { PURE_KIND_KEY = 1, PURE_KIND_MESSAGE = 2, PURE_KIND_TEXT = 3 } PureInputKind;
-typedef enum { PURE_FIELD_U32 = 1, PURE_FIELD_BYTES = 2 } PureFieldType;
+/* A message field: a u32le or a binary64 (fixed, at its offset in the
+ * payload's prefix), or bytes or text of any length. The prefix also holds
+ * each variable field's u32le length but the last one's (its offset is
+ * PURE_FIELD_REST), which takes what follows the others; the variable
+ * fields' bytes follow the prefix in declaration order. A text is UTF-8 and
+ * a number finite, or the message fails. */
+typedef enum { PURE_FIELD_U32 = 1, PURE_FIELD_BYTES = 2, PURE_FIELD_NUMBER = 3, PURE_FIELD_TEXT = 4 } PureFieldType;
+enum { PURE_FIELD_REST = UINT32_MAX };
 typedef enum {
     PURE_STATE_NUM = 0, PURE_STATE_TEXT = 1, PURE_STATE_CURSOR = 2, PURE_STATE_LIST = 3, PURE_STATE_INDEX = 4
 } PureStateType;