Made Database the mtt engine.

This commit is contained in:
2022-07-18 17:24:45 -04:00
parent dfa96dfc00
commit 620e5593e0
3 changed files with 8 additions and 7 deletions

179
src/morethantext/graphql.rs Normal file
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use async_graphql::{Context, EmptySubscription, Error, Object, Result, Schema};
use async_std::sync::RwLock;
use serde_json;
mod database;
#[derive(Clone)]
struct Table {
name: String,
}
impl Table {
async fn new(name: String) -> Self {
Self { name: name }
}
}
#[Object]
impl Table {
async fn name(&self) -> String {
self.name.to_string()
}
async fn describe(&self) -> Vec<u64> {
Vec::new()
}
}
struct Query;
#[Object]
impl Query {
async fn table(&self, ctx: &Context<'_>, name: String) -> Result<Option<Table>> {
let tbls = ctx
.data::<RwLock<Vec<Table>>>()
.unwrap()
.read()
.await
.to_vec();
match tbls.binary_search_by(|t| t.name.cmp(&name)) {
Ok(idx) => Ok(Some(tbls[idx].clone())),
Err(_) => Ok(None),
}
}
async fn tables(&self, ctx: &Context<'_>) -> Vec<Table> {
ctx.data::<RwLock<Vec<Table>>>()
.unwrap()
.read()
.await
.to_vec()
}
}
struct Mutation;
#[Object]
impl Mutation {
async fn create_table(&self, ctx: &Context<'_>, name: String) -> Result<Option<Table>> {
let mut tables = ctx.data::<RwLock<Vec<Table>>>().unwrap().write().await;
match tables.binary_search_by(|t| t.name.cmp(&name)) {
Ok(_) => Err(Error::new(format!("Table {} already exists.", &name))),
Err(_) => {
let output = Table::new(name).await;
tables.push(output.clone());
tables.sort_by_key(|k| k.name.clone());
Ok(Some(output))
}
}
}
}
#[derive(Clone)]
pub struct MoreThanText {
schema: Schema<Query, Mutation, EmptySubscription>,
}
impl MoreThanText {
pub fn new() -> Self {
let tables: Vec<Table> = Vec::new();
Self {
schema: Schema::build(Query, Mutation, EmptySubscription)
.data(RwLock::new(tables))
.finish(),
}
}
pub async fn execute(&self, qry: &str) -> String {
let res = self.schema.execute(qry).await;
serde_json::to_string(&res).unwrap()
}
}
#[cfg(test)]
mod support {
use super::*;
pub fn compare(db: &MoreThanText, output: &str, expected: &str) {
assert!(
output == expected,
"\n\n{}\nGot: {}\nWant: {}\n\n",
db.schema.sdl(),
output,
expected
);
}
}
#[cfg(test)]
mod queries {
use super::*;
#[async_std::test]
async fn list_table() {
let db = MoreThanText::new();
db.execute(r#"mutation {createTable(name: "wilma"){name}}"#)
.await;
db.execute(r#"mutation {createTable(name: "betty"){name}}"#)
.await;
let output = db.execute(r#"{table(name: "wilma"){name}}"#).await;
let expected = r#"{"data":{"table":{"name":"wilma"}}}"#;
support::compare(&db, &output, &expected);
}
#[async_std::test]
async fn list_no_table() {
let db = MoreThanText::new();
let output = db.execute(r#"{table(name: "slade"){name}}"#).await;
let expected = r#"{"data":{"table":null}}"#;
support::compare(&db, &output, &expected);
}
#[async_std::test]
async fn list_tables() {
let db = MoreThanText::new();
db.execute(r#"mutation {createTable(name: "fred"){name}}"#)
.await;
db.execute(r#"mutation {createTable(name: "barney"){name}}"#)
.await;
let output = db.execute(r#"{tables{name}}"#).await;
let expected = r#"{"data":{"tables":[{"name":"barney"},{"name":"fred"}]}}"#;
support::compare(&db, &output, &expected);
}
#[async_std::test]
async fn empty_table_description() {
let db = MoreThanText::new();
let output = db
.execute(r#"mutation {createTable(name: "pebbles"){name describe}}"#)
.await;
let expected = r#"{"data":{"createTable":{"name":"pebbles","describe":[]}}}"#;
support::compare(&db, &output, &expected);
}
}
#[cfg(test)]
mod mutations {
use super::*;
#[async_std::test]
async fn add_table() {
let db = MoreThanText::new();
let output = db
.execute(r#"mutation {createTable(name: "william"){name}}"#)
.await;
let expected = r#"{"data":{"createTable":{"name":"william"}}}"#;
support::compare(&db, &output, &expected);
}
#[async_std::test]
async fn cannot_add_duplicate_table() {
let db = MoreThanText::new();
let qry = r#"mutation {createTable(name: "gadzoo"){name}}"#;
db.execute(&qry).await;
let output = db.execute(qry).await;
let expected = r#"{"data":null,"errors":[{"message":"Table gadzoo already exists.","locations":[{"line":1,"column":11}],"path":["createTable"]}]}"#;
support::compare(&db, &output, &expected);
}
}

239
src/morethantext/mod.rs Normal file
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use async_std::sync::{Arc, RwLock};
use std::{collections::HashMap, error::Error, fmt, str::FromStr};
#[derive(Debug)]
pub struct DBError {
detail: String,
source: Option<Box<DBError>>,
}
impl DBError {
fn new(detail: String) -> Self {
Self {
detail: detail.to_string(),
source: None,
}
}
}
impl fmt::Display for DBError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", &self.detail)
}
}
impl Error for DBError {
fn source(&self) -> Option<&(dyn Error + 'static)> {
match &self.source {
Some(err) => Some(err),
None => None,
}
}
}
#[derive(Clone, PartialEq)]
pub enum FieldType {
Table,
}
impl fmt::Display for FieldType {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
FieldType::Table => write!(f, "table"),
}
}
}
impl FromStr for FieldType {
type Err = DBError;
fn from_str(input: &str) -> Result<FieldType, Self::Err> {
match input {
"table" => Ok(FieldType::Table),
_ => Err(DBError::new(format!("field type {} does not exist", input))),
}
}
}
pub struct Table {
fields: Arc<RwLock<HashMap<String, FieldType>>>,
}
impl Table {
pub async fn new() -> Self {
Self {
fields: Arc::new(RwLock::new(HashMap::new())),
}
}
pub async fn add_field(&self, name: &str, ftype: &str) -> Result<(), Box<dyn Error>> {
let ftype = match FieldType::from_str(ftype) {
Ok(field) => field,
Err(err) => {
let mut error = DBError::new(format!("failed to add field {}", name));
error.source = Some(Box::new(err));
return Err(Box::new(error));
}
};
let mut fmap = self.fields.write().await;
match fmap.get(name) {
Some(_) => Err(Box::new(DBError::new(format!(
"field {} already exists",
name
)))),
None => {
fmap.insert(name.to_string(), ftype);
Ok(())
}
}
}
pub async fn fields(&self) -> HashMap<String, FieldType> {
let fmap = self.fields.read().await;
fmap.clone()
}
}
#[derive(Clone)]
pub struct MoreThanText;
impl MoreThanText {
pub async fn new() -> Self {
Self {}
}
pub async fn add_table(&self, _name: String) -> Table {
Table::new().await
}
}
#[cfg(test)]
mod tables {
use super::*;
#[async_std::test]
async fn new_table() {
Table::new().await;
}
#[async_std::test]
async fn add_field() {
let table = Table::new().await;
let mut expected: HashMap<String, FieldType> = HashMap::new();
expected.insert("stan".to_string(), FieldType::Table);
expected.insert("lee".to_string(), FieldType::Table);
table.add_field("stan", "table").await.unwrap();
table.add_field("lee", "table").await.unwrap();
let output = table.fields().await;
assert!(output == expected, "Table did not get the fields added.");
}
#[async_std::test]
async fn add_bad_field() -> Result<(), String> {
let table = Table::new().await;
let name = "failure";
let bad_type = "ljksdbtt";
let expected = format!("failed to add field {}", name);
let source = format!("field type {} does not exist", bad_type);
match table.add_field(name, bad_type).await {
Ok(_) => Err("A bad field type should not return successfully".to_string()),
Err(err) => {
if format!("{}", err) != expected {
Err(format!("Got: '{}' - Want: '{}'", err, expected))
} else if format!("{}", err.source().unwrap()) != source {
Err(format!(
"Got: '{}' - Want: '{}'",
err.source().unwrap(),
source
))
} else {
Ok(())
}
}
}
}
#[async_std::test]
async fn add_duplicate_field() -> Result<(), String> {
let table = Table::new().await;
let name = "twice";
let expected = format!("field {} already exists", name);
table.add_field(name, "table").await.unwrap();
match table.add_field(name, "table").await {
Ok(_) => Err(format!("Cannot have two fields with named '{}'", name)),
Err(err) => {
if format!("{}", err) == expected {
Ok(())
} else {
Err(format!("Got: '{}' - Want: '{}'", err, expected))
}
}
}
}
}
#[cfg(test)]
mod databases {
use super::*;
#[async_std::test]
async fn new_database() {
MoreThanText::new().await;
}
#[async_std::test]
async fn add_table() {
let db = MoreThanText::new().await;
db.add_table("fred".to_string()).await;
}
}
#[cfg(test)]
mod fieldtypes {
use super::*;
fn get_field_map() -> HashMap<String, FieldType> {
let mut fields: HashMap<String, FieldType> = HashMap::new();
fields.insert("table".to_string(), FieldType::Table);
return fields;
}
#[test]
fn convert_to_string() {
for (key, value) in get_field_map().iter() {
assert!(
key == &value.to_string(),
"\n\nGot: {}\nWant: {}\n\n",
value.to_string(),
key
);
}
}
#[test]
fn convert_from_string() {
for (key, value) in get_field_map().iter() {
assert!(
&FieldType::from_str(key).unwrap() == value,
"\n\nDid not return a FieldType::{}",
key
);
}
}
#[test]
fn convert_from_string_error() -> Result<(), String> {
let ftype = "lkjsdfh";
let expected = format!("field type {} does not exist", ftype);
match FieldType::from_str(ftype) {
Ok(_) => Err(format!("Found field type {}", ftype)),
Err(err) => {
if format!("{}", err) == expected {
Ok(())
} else {
Err(format!("Got: '{}' - Want: '{}'", err, expected))
}
}
}
}
}