mentat/db/src/bootstrap.rs

// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

#![allow(dead_code)]

use ::{to_namespaced_keyword};
use edn;
use edn::types::Value;
use entids;
use errors::*;
use mentat_tx::entities::Entity;
use mentat_tx_parser;
use types::{IdentMap, Partition, PartitionMap, Schema, TypedValue};
use values;

/// The first transaction ID applied to the knowledge base.
///
/// This is the start of the :db.part/tx partition.
pub const TX0: i64 = 0x10000000;

lazy_static! {
    static ref V1_IDENTS: Vec<(&'static str, i64)> = {
        vec![(":db/ident",             entids::DB_IDENT),
             (":db.part/db",           entids::DB_PART_DB),
             (":db/txInstant",         entids::DB_TX_INSTANT),
             (":db.install/partition", entids::DB_INSTALL_PARTITION),
             (":db.install/valueType", entids::DB_INSTALL_VALUETYPE),
             (":db.install/attribute", entids::DB_INSTALL_ATTRIBUTE),
             (":db/valueType",         entids::DB_VALUE_TYPE),
             (":db/cardinality",       entids::DB_CARDINALITY),
             (":db/unique",            entids::DB_UNIQUE),
             (":db/isComponent",       entids::DB_IS_COMPONENT),
             (":db/index",             entids::DB_INDEX),
             (":db/fulltext",          entids::DB_FULLTEXT),
             (":db/noHistory",         entids::DB_NO_HISTORY),
             (":db/add",               entids::DB_ADD),
             (":db/retract",           entids::DB_RETRACT),
             (":db.part/user",         entids::DB_PART_USER),
             (":db.part/tx",           entids::DB_PART_TX),
             (":db/excise",            entids::DB_EXCISE),
             (":db.excise/attrs",      entids::DB_EXCISE_ATTRS),
             (":db.excise/beforeT",    entids::DB_EXCISE_BEFORE_T),
             (":db.excise/before",     entids::DB_EXCISE_BEFORE),
             (":db.alter/attribute",   entids::DB_ALTER_ATTRIBUTE),
             (":db.type/ref",          entids::DB_TYPE_REF),
             (":db.type/keyword",      entids::DB_TYPE_KEYWORD),
             (":db.type/long",         entids::DB_TYPE_LONG),
             (":db.type/double",       entids::DB_TYPE_DOUBLE),
             (":db.type/string",       entids::DB_TYPE_STRING),
             (":db.type/boolean",      entids::DB_TYPE_BOOLEAN),
             (":db.type/instant",      entids::DB_TYPE_INSTANT),
             (":db.type/bytes",        entids::DB_TYPE_BYTES),
             (":db.cardinality/one",   entids::DB_CARDINALITY_ONE),
             (":db.cardinality/many",  entids::DB_CARDINALITY_MANY),
             (":db.unique/value",      entids::DB_UNIQUE_VALUE),
             (":db.unique/identity",   entids::DB_UNIQUE_IDENTITY),
             (":db/doc",               entids::DB_DOC),
        ]
    };

    static ref V2_IDENTS: Vec<(&'static str, i64)> = {
        [(*V1_IDENTS).clone(),
         vec![(":db.schema/version",   entids::DB_SCHEMA_VERSION),
              (":db.schema/attribute", entids::DB_SCHEMA_ATTRIBUTE),
         ]].concat()
    };

    static ref V1_PARTS: Vec<(&'static str, i64, i64)> = {
        vec![(":db.part/db", 0, (1 + V1_IDENTS.len()) as i64),
             (":db.part/user", 0x10000, 0x10000),
             (":db.part/tx", TX0, TX0),
        ]
    };

    static ref V2_PARTS: Vec<(&'static str, i64, i64)> = {
        vec![(":db.part/db", 0, (1 + V2_IDENTS.len()) as i64),
             (":db.part/user", 0x10000, 0x10000),
             (":db.part/tx", TX0, TX0),
        ]
    };

    static ref V1_SYMBOLIC_SCHEMA: Value = {
        let s = r#"
{:db/ident             {:db/valueType   :db.type/keyword
                       :db/cardinality :db.cardinality/one
                       :db/unique      :db.unique/identity}
 :db.install/partition {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/many}
 :db.install/valueType {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/many}
 :db.install/attribute {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/many}
 ;; TODO: support user-specified functions in the future.
 ;; :db.install/function {:db/valueType :db.type/ref
 ;;                       :db/cardinality :db.cardinality/many}
 :db/txInstant         {:db/valueType   :db.type/long
                        :db/cardinality :db.cardinality/one
                        :db/index       true}
 :db/valueType         {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/one}
 :db/cardinality       {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/one}
 :db/doc               {:db/valueType   :db.type/string
                        :db/cardinality :db.cardinality/one}
 :db/unique            {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/one}
 :db/isComponent       {:db/valueType   :db.type/boolean
                        :db/cardinality :db.cardinality/one}
 :db/index             {:db/valueType   :db.type/boolean
                        :db/cardinality :db.cardinality/one}
 :db/fulltext          {:db/valueType   :db.type/boolean
                        :db/cardinality :db.cardinality/one}
 :db/noHistory         {:db/valueType   :db.type/boolean
                        :db/cardinality :db.cardinality/one}}"#;
        edn::parse::value(s)
            .map_err(|_| ErrorKind::BadBootstrapDefinition("Unable to parse V1_SYMBOLIC_SCHEMA".into()))
            .unwrap()
    };

    static ref V2_SYMBOLIC_SCHEMA: Value = {
        let s = r#"
{:db.alter/attribute   {:db/valueType   :db.type/ref
                        :db/cardinality :db.cardinality/many}
 :db.schema/version    {:db/valueType   :db.type/long
                        :db/cardinality :db.cardinality/one}

 ;; unique-value because an attribute can only belong to a single
 ;; schema fragment.
 :db.schema/attribute  {:db/valueType   :db.type/ref
                        :db/unique      :db.unique/value
                        :db/cardinality :db.cardinality/many}}"#;
        let right = edn::parse::value(s)
            .map_err(|_| ErrorKind::BadBootstrapDefinition("Unable to parse V2_SYMBOLIC_SCHEMA".into()))
            .unwrap();
        edn::utils::merge(&V1_SYMBOLIC_SCHEMA, &right)
            .ok_or(ErrorKind::BadBootstrapDefinition("Unable to parse V2_SYMBOLIC_SCHEMA".into()))
            .unwrap()
    };
}

/// Convert (ident, entid) pairs into [:db/add IDENT :db/ident IDENT] `Value` instances.
fn idents_to_assertions(idents: &[(&str, i64)]) -> Vec<Value> {
    idents
        .into_iter()
        .map(|&(ident, _)| {
            let value = Value::NamespacedKeyword(to_namespaced_keyword(&ident).unwrap());
            Value::Vector(vec![values::DB_ADD.clone(), value.clone(), values::DB_IDENT.clone(), value.clone()])
        })
        .collect()
}

/// Convert {:ident {:key :value ...} ...} to vec![(String(:ident), String(:key), TypedValue(:value)), ...].
///
/// Such triples are closer to what the transactor will produce when processing
/// :db.install/attribute assertions.
fn symbolic_schema_to_triples(ident_map: &IdentMap, symbolic_schema: &Value) -> Result<Vec<(String, String, TypedValue)>> {
    // Failure here is a coding error, not a runtime error.
    let mut triples: Vec<(String, String, TypedValue)> = vec![];
    // TODO: Consider `flat_map` and `map` rather than loop.
    match *symbolic_schema {
        Value::Map(ref m) => {
            for (ident, mp) in m {
                let ident = match ident {
                    &Value::NamespacedKeyword(ref ident) => ident.to_string(),
                    _ => bail!(ErrorKind::BadBootstrapDefinition(format!("Expected namespaced keyword for ident but got '{:?}'", ident)))
                };
                match *mp {
                    Value::Map(ref mpp) => {
                        for (attr, value) in mpp {
                            let attr = match attr {
                                &Value::NamespacedKeyword(ref attr) => attr.to_string(),
                                _ => bail!(ErrorKind::BadBootstrapDefinition(format!("Expected namespaced keyword for attr but got '{:?}'", attr)))
                            };

                            // We have symbolic idents but the transactor handles entids.  Ad-hoc
                            // convert right here.  This is a fundamental limitation on the
                            // bootstrap symbolic schema format; we can't represent "real" keywords
                            // at this time.
                            //
                            // TODO: remove this limitation, perhaps by including a type tag in the
                            // bootstrap symbolic schema, or by representing the initial bootstrap
                            // schema directly as Rust data.
                            let typed_value = match TypedValue::from_edn_value(value) {
                                Some(TypedValue::Keyword(ref s)) => TypedValue::Ref(*ident_map.get(s).ok_or(ErrorKind::UnrecognizedIdent(s.clone()))?),
                                Some(v) => v,
                                _ => bail!(ErrorKind::BadBootstrapDefinition(format!("Expected Mentat typed value for value but got '{:?}'", value)))
                            };

                            triples.push((ident.clone(),
                                       attr.clone(),
                                       typed_value));
                        }
                    },
                    _ => bail!(ErrorKind::BadBootstrapDefinition("Expected {:db/ident {:db/attr value ...} ...}".into()))
                }
            }
        },
        _ => bail!(ErrorKind::BadBootstrapDefinition("Expected {...}".into()))
    }
    Ok(triples)
}

/// Convert {IDENT {:key :value ...} ...} to [[:db/add IDENT :key :value] ...].
/// In addition, add [:db.add :db.part/db :db.install/attribute IDENT] installation assertions.
fn symbolic_schema_to_assertions(symbolic_schema: &Value) -> Result<Vec<Value>> {
    // Failure here is a coding error, not a runtime error.
    let mut assertions: Vec<Value> = vec![];
    match *symbolic_schema {
        Value::Map(ref m) => {
            for (ident, mp) in m {
                assertions.push(Value::Vector(vec![values::DB_ADD.clone(),
                                                   values::DB_PART_DB.clone(),
                                                   values::DB_INSTALL_ATTRIBUTE.clone(),
                                                   ident.clone()]));
                match *mp {
                    Value::Map(ref mpp) => {
                        for (attr, value) in mpp {
                            assertions.push(Value::Vector(vec![values::DB_ADD.clone(),
                                                               ident.clone(),
                                                               attr.clone(),
                                                               value.clone()]));
                        }
                    },
                    _ => bail!(ErrorKind::BadBootstrapDefinition("Expected {:db/ident {:db/attr value ...} ...}".into()))
                }
            }
        },
        _ => bail!(ErrorKind::BadBootstrapDefinition("Expected {...}".into()))
    }
    Ok(assertions)
}

pub fn bootstrap_partition_map() -> PartitionMap {
    V2_PARTS[..].iter()
        .map(|&(part, start, index)| (part.to_string(), Partition::new(start, index)))
        .collect()
}

pub fn bootstrap_ident_map() -> IdentMap {
    V2_IDENTS[..].iter()
        .map(|&(ident, entid)| (ident.to_string(), entid))
        .collect()
}

pub fn bootstrap_schema() -> Schema {
    let ident_map = bootstrap_ident_map();
    let bootstrap_triples = symbolic_schema_to_triples(&ident_map, &V2_SYMBOLIC_SCHEMA).unwrap();
    Schema::from_ident_map_and_triples(ident_map, bootstrap_triples).unwrap()
}

pub fn bootstrap_entities() -> Vec<Entity> {
    let bootstrap_assertions: Value = Value::Vector([
        symbolic_schema_to_assertions(&V2_SYMBOLIC_SCHEMA).unwrap(),
        idents_to_assertions(&V2_IDENTS[..]),
    ].concat());

    // Failure here is a coding error (since the inputs are fixed), not a runtime error.
    // TODO: represent these bootstrap data errors rather than just panicing.
    let bootstrap_entities: Vec<Entity> = mentat_tx_parser::Tx::parse(&[bootstrap_assertions][..]).unwrap();
    return bootstrap_entities;
}