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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/* $Rev$ $Date$ */
/**
* PostgreSQL-based database component implementation.
*/
#define WANT_HTTPD_LOG 1
#include "string.hpp"
#include "function.hpp"
#include "list.hpp"
#include "value.hpp"
#include "monad.hpp"
#include "parallel.hpp"
#include "pgsql.hpp"
namespace tuscany {
namespace sqldb {
/**
* Get an item from the database.
*/
const failable<value> get(const list<value>& params, const pgsql::PGSql& pg) {
return pgsql::get(car(params), pg);
}
/**
* Post an item to the database.
*/
const failable<value> post(const list<value>& params, const pgsql::PGSql& pg) {
const value id = append<value>(car(params), mklist(mkuuid()));
const failable<bool> val = pgsql::post(id, cadr(params), pg);
if (!hasContent(val))
return mkfailure<value>(val);
return id;
}
/**
* Put an item into the database.
*/
const failable<value> put(const list<value>& params, const pgsql::PGSql& pg) {
const failable<bool> val = pgsql::put(car(params), cadr(params), pg);
if (!hasContent(val))
return mkfailure<value>(val);
return value(content(val));
}
/**
* Patch an item in the database.
*/
const failable<value> patch(const list<value>& params, const pgsql::PGSql& pg) {
// Read patch
value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
if (isNull(p))
return mkfailure<value>("Couldn't read patch script");
const string script = cadr<value>(p);
debug(script, "pgsql::patch::script");
const lambda<const failable<value>(const value&, const pgsql::PGSql&, const string&, const int)> tryPatch = [&tryPatch](const value& key, const pgsql::PGSql& pg, const string& script, const int count) -> const failable<value> {
// Begin database transaction
const failable<bool> brc = pgsql::begin(pg);
if (!hasContent(brc))
return mkfailure<value>(brc);
// Get existing value from database
const failable<value> ival = pgsql::get(key, pg);
if (!hasContent(ival) && rcode(ival) != 404) {
pgsql::rollback(pg);
return mkfailure<value>(ival);
}
// Apply patch
istringstream is(script);
scheme::Env env = scheme::setupEnvironment();
const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(key, hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
if (isNull(pval)) {
ostringstream os;
os << "Couldn't patch postgresql entry: " << key;
return mkfailure<value>(str(os), 404, false);
}
// Push patched value to database
const failable<bool> val = pgsql::patch(key, pval, pg);
if (!hasContent(val)) {
pgsql::rollback(pg);
// Retry on a transaction serialization error
if (rcode(val) == 409 && count > 0)
return tryPatch(key, pg, script, count - 1);
return mkfailure<value>(val);
}
// Commit database transaction
const failable<bool> crc = pgsql::commit(pg);
if (!hasContent(crc))
return mkfailure<value>(crc);
return value(content(val));
};
// Try patching the entry and automatically retry a few times on transaction
// serialization errors
return tryPatch(car(params), pg, script, 5);
}
/**
* Delete an item from the database.
*/
const failable<value> del(const list<value>& params, const pgsql::PGSql& pg) {
const failable<bool> val = pgsql::del(car(params), pg);
if (!hasContent(val))
return mkfailure<value>(val);
return value(content(val));
}
/**
* Start the component.
*/
const failable<value> start(const list<value>& params) {
// Connect to the configured database and table
debug("sqldb::start");
const gc_pool cp(gc_current_pool());
const value conninfo = ((lvvlambda)car(params))(nilListValue);
const value table = ((lvvlambda)cadr(params))(nilListValue);
const lambda<const gc_ptr<pgsql::PGSql>()> newPGSql = [conninfo, table, cp]() -> const gc_ptr<pgsql::PGSql> {
debug("sqldb::newPGSql");
const gc_scoped_pool sp(pool(cp));
return new (gc_new<pgsql::PGSql>()) pgsql::PGSql(conninfo, table);
};
const perthread_ptr<pgsql::PGSql> pg = *(new (gc_new<perthread_ptr<pgsql::PGSql> >()) perthread_ptr<pgsql::PGSql>(newPGSql));
// Return the component implementation lambda function
const lvvlambda applySqldb = [pg](const list<value>& params) -> const value {
const value func(car(params));
if (func == "get")
return get(cdr(params), *pg);
if (func == "post")
return post(cdr(params), *pg);
if (func == "put")
return put(cdr(params), *pg);
if (func == "patch")
return patch(cdr(params), *pg);
if (func == "delete")
return del(cdr(params), *pg);
return mkfailure<value>();
};
return value(applySqldb);
}
}
}
extern "C" {
const tuscany::value apply(const tuscany::list<tuscany::value>& params) {
const tuscany::value func(car(params));
if (func == "start")
return tuscany::sqldb::start(cdr(params));
return tuscany::mkfailure<tuscany::value>();
}
}
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