jdb/lib/jdb.js

A database that hacks.

// Generated by CoffeeScript 1.9.3
var Promise, fs,
  slice = [].slice;

fs = require('fs');

Promise = require('yaku');

module.exports = function() {
  var ego, self;
  self = {
    init: function(options) {
      Object.defineProperty(self, 'doc', {
        get: function() {
          return ego.doc;
        }
      });
      ego.init_options(options);
      return ego.init_db_file().then(function() {
        ego.db_file = fs.createWriteStream(ego.opts.dbPath, {
          flags: 'a',
          encoding: 'utf8'
        });
        return null;
      });
    },
    exec: function(data, command, callback) {
      var err, jdb, opts, ref;
      if (arguments.length === 0) {
        return;
      } else if (typeof data === 'function') {
        callback = command;
        command = data;
      } else if (arguments.length === 1) {
        ref = data, data = ref.data, command = ref.command, callback = ref.callback;
      }
      opts = {
        data: data,
        command: command,
        callback: callback
      };
      if (!opts.command) {
        return;
      }
      jdb = ego.generate_api(opts);
      try {
        opts.command(jdb, opts.data);
      } catch (_error) {
        err = _error;
        err.promise = jdb.rollback();
        if (opts.callback) {
          err.promise.then(function() {
            return opts.callback(err);
          });
        } else {
          if (ego.opts.promise) {
            opts.deferred.reject(err);
          }
        }
      }
      if (ego.opts.promise) {
        return opts.deferred.promise;
      }
    },
    compactDBFile: function() {
      ego.is_compressing = true;
      return ego.promisify(fs.writeFile)(ego.opts.dbPath, ego.compacted_data()).then(function() {
        ego.is_compressing = false;
        ego.write_queue.forEach(function(fn) {
          return fn();
        });
        return ego.write_queue = [];
      }).then();
    },
    compactDBFileSync: function() {
      return fs.writeFileSync(ego.opts.dbPath, ego.compacted_data());
    },
    close: function() {
      return ego.promisify(ego.db_file.end, ego.db_file)();
    }
  };
  ego = {
    opts: {
      dbPath: 'jdb.db',
      compactDBFile: true,
      promise: true
    },
    doc: {},
    db_file: null,
    is_compressing: false,
    write_queue: [],
    init_options: function(options) {
      var k, ref, results, v;
      if (!options) {
        return;
      }
      ref = ego.opts;
      results = [];
      for (k in ref) {
        v = ref[k];
        if (options[k] !== void 0) {
          results.push(ego.opts[k] = options[k]);
        } else {
          results.push(void 0);
        }
      }
      return results;
    },
    init_db_file: function() {
      if (fs.existsSync(ego.opts.dbPath)) {
        return ego.load_data().then(function() {
          if (ego.opts.compactDBFile) {
            return self.compactDBFile();
          }
        });
      } else {
        return self.compactDBFile();
      }
    },
    load_data: function() {
      var buf, is_first_line, jdb_ref, readline, rl;
      readline = require('readline');
      rl = readline.createInterface({
        input: fs.createReadStream(ego.opts.dbPath, {
          encoding: 'utf8'
        }),
        output: process.stdout,
        terminal: false
      });
      buf = '';
      jdb_ref = null;
      is_first_line = true;
      return new Promise(function(resolve, reject) {
        var error, isRejected;
        isRejected = false;
        error = function(err) {
          if (isRejected) {
            return;
          } else {
            isRejected = true;
          }
          if (jdb_ref && typeof jdb_ref.doc === 'object') {
            ego.doc = jdb_ref.doc;
          }
          return reject(err);
        };
        rl.on('line', function(line) {
          var err, jdb;
          if (line[0] === '(') {
            try {
              if (is_first_line) {
                jdb_ref = eval(buf + '; jdb');
                is_first_line = false;
              } else {
                jdb = jdb_ref;
                eval(buf);
              }
            } catch (_error) {
              err = _error;
              error(err);
            }
            return buf = line;
          } else {
            return buf += '\n' + line;
          }
        });
        return rl.on('close', function() {
          var err, jdb;
          try {
            jdb = jdb_ref;
            eval(buf);
            if (jdb && typeof jdb.doc === 'object') {
              ego.doc = jdb.doc;
              return resolve();
            } else {
              return self.compactDBFile()["catch"](function(err) {
                return error(err);
              }).then(function() {
                return resolve();
              });
            }
          } catch (_error) {
            err = _error;
            return error(err);
          }
        });
      });
    },
    generate_api: function(opts) {
      var is_rolled_back, is_sent, jdb;
      if (ego.opts.promise) {
        opts.deferred = {};
        opts.deferred.promise = new Promise(function(resolve, reject) {
          opts.deferred.resolve = resolve;
          return opts.deferred.reject = reject;
        });
      }
      is_sent = false;
      is_rolled_back = false;
      jdb = {
        send: function(data) {
          if (is_sent) {
            return;
          } else {
            is_sent = true;
          }
          if (typeof opts.callback === "function") {
            opts.callback(null, data);
          }
          if (ego.opts.promise) {
            return opts.deferred.resolve(data);
          }
        },
        save: function(data) {
          var cmd_data, indented_cmd;
          if (is_rolled_back) {
            return;
          }
          indented_cmd = opts.command.toString().replace(/^function([\s\S]+)\}$/, function(m, p) {
            return 'function' + p.replace(/\n\(/g, '\n (') + '}';
          });
          cmd_data = "(" + indented_cmd + ")(jdb, " + (JSON.stringify(opts.data)) + ");\n";
          if (ego.is_compressing) {
            return ego.write_queue.push(function() {
              return ego.db_file.write(cmd_data, function() {
                return jdb.send(data);
              });
            });
          } else {
            return ego.db_file.write(cmd_data, function() {
              return jdb.send(data);
            });
          }
        },
        rollback: function() {
          is_rolled_back = true;
          return ego.load_data();
        },
        doc: ego.doc
      };
      return jdb;
    },
    compacted_data: function() {
      return "var jdb = { doc: " + (JSON.stringify(ego.doc)) + ", send: function() {}, save: function() {}, rollback: function() {} };\n";
    },
    promisify: function(fn, self) {
      return function() {
        var args;
        args = 1 <= arguments.length ? slice.call(arguments, 0) : [];
        return new Promise(function(resolve, reject) {
          args.push(function() {
            if (arguments[0] != null) {
              return reject(arguments[0]);
            } else {
              return resolve(arguments[1]);
            }
          });
          return fn.apply(self, args);
        });
      };
    }
  };
  return self;
};