SQLite engine: streams — StreamHandle, extent-guarded reads, trim, durable subscribe (task sqlite-engine-streams)

alkstore-sqlite/src/tx.rs

@@ -32,6 +32,7 @@ use crate::resolution::{
     resolve_enqueue_opts,
 };
 use crate::seam::{blocking, sqlite_error};
+use crate::stream::stream_events_from_json_page;
 use crate::substrate::{
     Stamps, Writer, enqueue, get_job, stream_get_offset, stream_publish, stream_read_since,
     stream_save_offset,
@@ -491,36 +492,3 @@ fn job_from_json(value: &serde_json::Value) -> Result<Option<Job>> {
         opt_field("died_at")?,
     )))
 }
-
-/// Decode the substrate's stream-page JSON into the contract's
-/// [`StreamEvent`] values (`from_row` — `topic` carries the contract's
-/// `stream`).
-fn stream_events_from_json_page(page: &str, stream: String) -> Result<Vec<StreamEvent>> {
-    let array: serde_json::Value = serde_json::from_str(page)
-        .map_err(|e| Error::Codec(format!("stream page must be json: {e}")))?;
-    let rows = array
-        .as_array()
-        .ok_or_else(|| Error::Codec("stream page must be a json array".to_string()))?;
-    let mut out = Vec::with_capacity(rows.len());
-    for row in rows {
-        out.push(StreamEvent::from_row(
-            serde_json::from_value(row["offset"].clone())
-                .map_err(|e| Error::Codec(format!("stream row offset must be i64: {e}")))?,
-            stream.clone(),
-            if row["key"].is_null() {
-                None
-            } else {
-                serde_json::from_value(row["key"].clone())
-                    .map_err(|e| Error::Codec(format!("stream row key must be a string: {e}")))?
-            },
-            row["payload"]
-                .as_str()
-                .ok_or_else(|| Error::Codec("stream row payload must be a string".to_string()))?
-                .as_bytes()
-                .to_vec(),
-            serde_json::from_value(row["created_at"].clone())
-                .map_err(|e| Error::Codec(format!("stream row created_at must be i64: {e}")))?,
-        ));
-    }
-    Ok(out)
-}