Mercurial > lbo > hg > async-google-apis
view generate/generate.py @ 8:755f08722795
Work on generating services
author | Lewin Bormann <lbo@spheniscida.de> |
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date | Sat, 17 Oct 2020 13:04:25 +0200 |
parents | f098e2637387 |
children | bcd017d6c863 |
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#!/usr/bin/env python3 import argparse import chevron import json import re import requests from os import path ResourceStructTmpl = ''' #[derive(Serialize, Deserialize, Debug, Clone, Default)] pub struct {{name}} { {{#fields}} {{#comment}} // {{comment}} {{/comment}} {{{attr}}} {{name}}: {{{typ}}}, {{/fields}} } ''' def optionalize(name, optional=True): return 'Option<{}>'.format(name) if optional else name def replace_keywords(name): return { 'type': ('typ', 'type'), }.get(name, name) def capitalize_first(name): return name[0].upper() + name[1:] def snake_case(name): def r(c): if c.islower(): return c return '_' + c.lower() return ''.join([r(c) for c in name]) def type_of_property(name, prop, optional=True): """Translate a JSON schema type into Rust types. Arguments: name: Name of the property. If the property is an object with fixed fields, generate a struct with this name. prop: A JSON object from a discovery document representing a type. Returns: type (string|tuple), structs (list of dicts) where type is a string representing a Rust type, or a tuple where the first element is a Rust type and the second element is a comment detailing the use of the field. The list of dicts returned as structs are any structs that need to be separately implemented and that the generated struct (if it was a struct) depends on. """ typ = '' comment = '' structs = [] try: if '$ref' in prop: return optionalize(prop['$ref'], optional), structs if 'type' in prop and prop['type'] == 'object': if 'properties' in prop: typ = name struct = {'name': name, 'fields': []} for pn, pp in prop['properties'].items(): subtyp, substructs = type_of_property(name + capitalize_first(pn), pp, optional=True) if type(subtyp) is tuple: subtyp, comment = subtyp else: comment = None cleaned_pn = replace_keywords(pn) if type(cleaned_pn) is tuple: jsonname = cleaned_pn[1] cleaned_pn = snake_case(cleaned_pn[0]) else: jsonname = pn cleaned_pn = snake_case(cleaned_pn) struct['fields'].append({ 'name': cleaned_pn, 'attr': '#[serde(rename = "{}")]'.format(jsonname), 'typ': subtyp, 'comment': comment }) structs.extend(substructs) structs.append(struct) return (optionalize(typ, optional), prop.get('description', '')), structs if 'additionalProperties' in prop: field, substructs = type_of_property(name, prop['additionalProperties'], optional=False) structs.extend(substructs) if type(field) is tuple: typ = field[0] else: typ = field return (optionalize('HashMap<String,' + typ + '>', optional), prop.get('description', '')), structs if prop['type'] == 'array': typ, substructs = type_of_property(name, prop['items'], optional=False) if type(typ) is tuple: typ = typ[0] return (optionalize('Vec<' + typ + '>', optional), prop.get('description', '')), structs + substructs if prop['type'] == 'string': if 'format' in prop: if prop['format'] == 'int64': return (optionalize('String', optional), 'i64: ' + prop.get('description', '')), structs if prop['format'] == 'int32': return (optionalize('String', optional), 'i32: ' + prop.get('description', '')), structs if prop['format'] == 'double': return (optionalize('String', optional), 'f64: ' + prop.get('description', '')), structs if prop['format'] == 'float': return (optionalize('String', optional), 'f32: ' + prop.get('description', '')), structs if prop['format'] == 'date-time': return (optionalize('DateTime<Utc>', optional), prop.get('description', '')), structs return (optionalize('String', optional), prop.get('description', '')), structs if prop['type'] == 'boolean': return (optionalize('bool', optional), prop.get('description', '')), structs if prop['type'] in ('number', 'integer'): if prop['format'] == 'float': return (optionalize('f32', optional), prop.get('description', '')), structs if prop['format'] == 'double': return (optionalize('f64', optional), prop.get('description', '')), structs if prop['format'] == 'int32': return (optionalize('i32', optional), prop.get('description', '')), structs if prop['format'] == 'int64': return (optionalize('i64', optional), prop.get('description', '')), structs raise Exception('unimplemented!', name, prop) except KeyError as e: print(name, prop) print(e) raise e def resolve_parameters(string, paramsname='params', suffix='.unwrap()'): """Returns a Rust syntax for formatting the given string with API parameters, and a list of (snake-case) API parameters that are used. """ pat = re.compile('\{(\w+)\}') params = re.findall(pat, string) snakeparams = [snake_case(p) for p in params] format_params = ','.join(['{}={}.{}{}'.format(p, paramsname, sp, suffix) for (p, sp) in zip(params, snakeparams)]) return 'format!("{}", {})'.format(string, format_params), snakeparams def generate_service(resource, methods, discdoc): service = capitalize_first(resource) parts = [] parts.append('pub struct {}Service {{'.format(service)) parts.append(' client: TlsClient,') parts.append(' authenticator: Authenticator,') parts.append('}') parts.append('') parts.append('impl {}Service {{'.format(service)) for methodname, method in methods['methods'].items(): params_name = service+capitalize_first(methodname)+'Params' in_type = method['request']['$ref'] if 'request' in method else '()' out_type = method['response']['$ref'] if 'response' in method else '()' is_upload = 'mediaUpload' in method if is_upload: parts.append(' fn {}(&mut self, params: {}, req: {}) -> Result<{}> {{'.format( snake_case(methodname), params_name, in_type, out_type)) else: parts.append(' fn {}(&mut self, params: {}, req: {}, data: &hyper::body::Bytes) -> Result<{}> {{'.format( snake_case(methodname), params_name, in_type, out_type)) formatted_path, required_params = resolve_parameters(method['path']) for rp in required_params: parts.append(' if params.{}.is_none() {{'.format(rp)) parts.append(' return Err(Error::new(ApiError::InputDataError("Parameter {} is missing!".to_string())));'.format(rp)) parts.append(' }') parts.append(' let relpath = {};'.format(formatted_path)) parts.append(' unimplemented!()') parts.append(' }') parts.append('}') parts.append('') return '\n'.join(parts) def generate_structs(discdoc): schemas = discdoc['schemas'] resources = discdoc['resources'] structs = [] services = [] for name, desc in schemas.items(): typ, substructs = type_of_property(name, desc) structs.extend(substructs) for name, res in resources.items(): for methodname, method in res['methods'].items(): if 'parameters' not in method: structs.append({ 'name': '{}{}Params'.format(capitalize_first(name), capitalize_first(methodname)), 'fields': [] }) else: params = method['parameters'] typ = {'type': 'object', 'properties': params} typ, substructs = type_of_property( '{}{}Params'.format(capitalize_first(name), capitalize_first(methodname)), typ) structs.extend(substructs) for resource, methods in resources.items(): services.append(generate_service(resource, methods, discdoc)) modname = (discdoc['id'] + '_types').replace(':', '_') with open(path.join('gen', modname + '.rs'), 'w') as f: f.writelines([ 'use serde::{Deserialize, Serialize};\n', 'use chrono::{DateTime, Utc};\n', 'use anyhow::{Error, Result};\n', 'use std::collections::HashMap;\n', ''' type TlsConnr = hyper_rustls::HttpsConnector<hyper::client::HttpConnector>; type TlsClient = hyper::Client<TlsConnr, hyper::Body>; type Authenticator = yup_oauth2::authenticator::Authenticator<TlsConnr>; #[derive(Debug, Clone)] pub enum ApiError { InputDataError(String), } impl std::error::Error for ApiError {} impl std::fmt::Display for ApiError { fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { std::fmt::Debug::fmt(self, f) } } ''', ]) for s in structs: for field in s['fields']: if field.get('comment', None): field['comment'] = field['comment'].replace('\n', ' ') f.write(chevron.render(ResourceStructTmpl, s)) for s in services: f.write(s) f.write('\n') def fetch_discovery_base(url, apis): '''Fetch the discovery base document from `url`. Return api documents for APIs with IDs in `apis`. Returns: List of API JSON documents. ''' doc = json.loads(requests.get(url).text) return [it for it in doc['items'] if it['id'] in apis] def fetch_discovery_doc(api_doc): url = api_doc['discoveryRestUrl'] return json.loads(requests.get(url).text) def main(): p = argparse.ArgumentParser(description='Generate Rust code for asynchronous REST Google APIs.') p.add_argument('--discovery_base', default='https://www.googleapis.com/discovery/v1/apis', help='Base Discovery document.') p.add_argument('--only_apis', default='drive:v3', help='Only process APIs with these IDs (comma-separated)') args = p.parse_args() print(args.only_apis) docs = fetch_discovery_base(args.discovery_base, args.only_apis) for doc in docs: discdoc = fetch_discovery_doc(doc) #print(json.dumps(discdoc, sort_keys=True, indent=2)) generate_structs(discdoc) if __name__ == '__main__': main()