zcash_client_sqlite::query::get_*_memo_as_utf8()

zcash_client_sqlite/src/query.rs

@@ -2,7 +2,7 @@
 
 use rusqlite::Connection;
 use std::path::Path;
-use zcash_primitives::transaction::components::Amount;
+use zcash_primitives::{note_encryption::Memo, transaction::components::Amount};
 
 use crate::{
     error::{Error, ErrorKind},
@@ -91,6 +91,74 @@ pub fn get_verified_balance<P: AsRef<Path>>(db_data: P, account: u32) -> Result<
     }
 }
 
+/// Returns the memo for a received note, if it is known and a valid UTF-8 string.
+///
+/// The note is identified by its row index in the `received_notes` table within the data
+/// database.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_sqlite::query::get_received_memo_as_utf8;
+///
+/// let memo = get_received_memo_as_utf8("/path/to/data.db", 27);
+pub fn get_received_memo_as_utf8<P: AsRef<Path>>(
+    db_data: P,
+    id_note: i64,
+) -> Result<Option<String>, Error> {
+    let data = Connection::open(db_data)?;
+
+    let memo: Vec<_> = data.query_row(
+        "SELECT memo FROM received_notes
+        WHERE id_note = ?",
+        &[id_note],
+        |row| row.get(0),
+    )?;
+
+    match Memo::from_bytes(&memo) {
+        Some(memo) => match memo.to_utf8() {
+            Some(Ok(res)) => Ok(Some(res)),
+            Some(Err(e)) => Err(Error(ErrorKind::InvalidMemo(e))),
+            None => Ok(None),
+        },
+        None => Ok(None),
+    }
+}
+
+/// Returns the memo for a sent note, if it is known and a valid UTF-8 string.
+///
+/// The note is identified by its row index in the `sent_notes` table within the data
+/// database.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_sqlite::query::get_sent_memo_as_utf8;
+///
+/// let memo = get_sent_memo_as_utf8("/path/to/data.db", 12);
+pub fn get_sent_memo_as_utf8<P: AsRef<Path>>(
+    db_data: P,
+    id_note: i64,
+) -> Result<Option<String>, Error> {
+    let data = Connection::open(db_data)?;
+
+    let memo: Vec<_> = data.query_row(
+        "SELECT memo FROM sent_notes
+        WHERE id_note = ?",
+        &[id_note],
+        |row| row.get(0),
+    )?;
+
+    match Memo::from_bytes(&memo) {
+        Some(memo) => match memo.to_utf8() {
+            Some(Ok(res)) => Ok(Some(res)),
+            Some(Err(e)) => Err(Error(ErrorKind::InvalidMemo(e))),
+            None => Ok(None),
+        },
+        None => Ok(None),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use tempfile::NamedTempFile;