Differential D6854 Diff 23138 services/rust-lib/src/database.rs

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services/rust-lib/src/database.rs

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				use aws_sdk_dynamodb::{model::AttributeValue, Error as DynamoDBError};
				use chrono::{DateTime, Utc};
				use std::fmt::{Display, Formatter};

				#[derive(
				Debug, derive_more::Display, derive_more::From, derive_more::Error,
				)]
				pub enum Error {
				#[display(...)]
				AwsSdk(DynamoDBError),
				#[display(...)]
				Attribute(DBItemError),
				}

				#[derive(Debug, derive_more::Error, derive_more::Constructor)]
				pub struct DBItemError {
				attribute_name: &'static str,
				attribute_value: Option<AttributeValue>,
				attribute_error: DBItemAttributeError,
				}

				impl Display for DBItemError {
				fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
				match &self.attribute_error {
				DBItemAttributeError::Missing => {
				write!(f, "Attribute {} is missing", self.attribute_name)
				}
				DBItemAttributeError::IncorrectType => write!(
				f,
				"Value for attribute {} has incorrect type: {:?}",
				self.attribute_name, self.attribute_value
				),
				error => write!(
				f,
				"Error regarding attribute {} with value {:?}: {}",
				self.attribute_name, self.attribute_value, error
				),
				}
				}
				}

				#[derive(Debug, derive_more::Display, derive_more::Error)]
				pub enum DBItemAttributeError {
				#[display(...)]
				Missing,
				#[display(...)]
				IncorrectType,
				#[display(...)]
				InvalidTimestamp(chrono::ParseError),
				}

				pub fn parse_string_attribute(
				attribute_name: &'static str,
				attribute_value: Option<AttributeValue>,
				) -> Result<String, DBItemError> {
				match attribute_value {
				Some(AttributeValue::S(value)) => Ok(value),
				Some(_) => Err(DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::IncorrectType,
				)),
				None => Err(DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::Missing,
				)),
				}
				}

				pub fn parse_bool_attribute(
				attribute_name: &'static str,
				attribute_value: Option<AttributeValue>,
				) -> Result<bool, DBItemError> {
				match attribute_value {
				Some(AttributeValue::Bool(value)) => Ok(value),
				Some(_) => Err(DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::IncorrectType,
				)),
				None => Err(DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::Missing,
				)),
				}
				}

				pub fn parse_datetime_attribute(
				attribute_name: &'static str,
				attribute_value: Option<AttributeValue>,
				) -> Result<DateTime<Utc>, DBItemError> {
				if let Some(AttributeValue::S(datetime)) = &attribute_value {
				// parse() accepts a relaxed RFC3339 string
				datetime.parse().map_err(\|e\| {
				DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::InvalidTimestamp(e),
				)
				})
				} else {
				Err(DBItemError::new(
				attribute_name,
				attribute_value,
				DBItemAttributeError::Missing,
				))
				}
				}