There isn't a license for the project right now. LevelDB itself is New BSD licensed. I use the Apache license for my project. In any case, I think it would be a good thing to have a LICENSE file in the repo at some point.

When I try to run demo/million.js I get the following error:

rehanift@rehan-laptop:~/src/node-leveldb$ node demo/million.js 
Creating test database

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
TypeError: Argument 1 must be a string: DB.open(<filename>, <options?>, <callback?>)
    at Object.<anonymous> (/home/rehanift/src/node-leveldb/demo/million.js:6:4)
    at Module._compile (module.js:441:26)
    at Object..js (module.js:459:10)
    at Module.load (module.js:348:31)
    at Function._load (module.js:308:12)
    at Array.0 (module.js:479:10)
    at EventEmitter._tickCallback (node.js:192:40)

right now with iterator.forRange there is no way to know when the iterator has finished. ideally creating an iterator return a readable Stream

Wouldn't it be more convenient to use JavaScript instead of CoffeScript for the non C++ parts?

I find it very hard to read CoffeeScript code and so do many others and would say that such an essential library use as less dependencies as possible, since it doesn't make anything easier.

What's the reason for using CoffeeScript?

As far as I know there is currently no way to execute a callback if the iterator.forEach() method has reached limitKey.

Maybe I'm just not seeing how to do this (I'm quite new to node), but if there isn't one, would it be possible to add an additional callback (or something similar)?

I know the 0.10 version is still in development, but thought I'd share this issue with getting the latest version to even be recognized:

package.json

{
    "dependencies":{
        "leveldb":"git://github.com/my8bird/node-leveldb.git#dev/update_0.10"
    }
}

app.js

var leveldb = require('leveldb');
console.log(leveldb);

result

$ node app.js 

module.js:340
    throw err;
          ^
Error: Cannot find module 'leveldb'

I'm not too familiar with node (yet), but the package.json file in the leveldb module indicates "main": "lib", however, after npm installs the package, there is no lib folder in the leveldb folder. Should there be? I see lib is in the .gitignore file, so I'm guessing something is supposed to build that, but what? I did get a "build" folder as part of the npm install process, however.

OS X 10.6.8, node v0.10.5, npm 1.2.18

The full NPM install log is pasted here.

When running the test suite this error is shown and should be resolved.

path.exists is now called fs.exists

Some recent update in node-leveldb broke BitcoinJS:

https://github.com/bitcoinjs/bitcoinjs-server/issues/61#issuecomment-3876406

This database call is returning a string for some reason:

  var getBlockByHeight = this.getBlockByHeight =
  function getBlockByHeight(height, callback) {
    height = formatHeightKey(height);
    Step(
      function () {
        bBlockHeightIndex.get(height, true, this);
      },
      function (err, result) {
        if (err) throw err;

        console.log(Buffer.isBuffer(result), typeof result);

        if (!result) {
          this(null, null);
        } else {
          getBlockByHash(result, this);
        }
      },
      callback
    );
  };

The output of the debug statement is:

false 'string'

The result seems to be the correct result, just as a string, not as a buffer. Note that the second parameter of the get() call is true. What's even stranger: In other places asBuffer seems to work correctly.

Since keeping up with V8 and Node changes is quite a challenge and we have a very active community around the LevelUP (JS) and LevelDOWN (C++) packages exposing LevelDB in Node perhaps you would consider allowing us to start publishing code under the "leveldb" name in npm? We get occasional bug reports about people trying to install our packages but using "leveldb" instead. There's also people new to the ecosystem who just pick the name because it's logical (e.g.).
We would bump the major version and leave historical releases intact for anyone that might still have old systems using working versions of this code.
Cheers.

if you do npm install leveldb it works but if you add leveldb as a dependency in your package.json and then do npm install it fails on the coffeescript compile line of the makefile

i switched the compile line to these two lines and it succeeded for me:

coffee --bare --compile --output lib src/coffee/*.coffee
coffee --bare --compile --output lib src/coffee/leveldb/*.coffee

Hi,

I noticed that the last commit to handle.coffe, the synchronous open was dropped.

Is there a plan to support it again?

I'm getting this when trying to open a database created by a earlier version of node-leveldb

Corruption: corrupted compressed block contents

This discussion suggests the error might be caused by leveldb being built without snappy support: http://comments.gmane.org/gmane.comp.db.leveldb/911

I'm getting a build error on Mac OS X (10.7), with node v0.6.2, when I do an npm install leveldb

/Users/john/node_modules/leveldb/deps/leveldb/port/port_posix.h:20:22: error: 
endian.h: No such file or directory

However, if I clone the source from master, it builds fine.

Hi,
I know that sharing the same leveldb instance between various processes is discouraged, but I was wondering if it could work in case of node.js core cluster where only master process would update database and workers would only query db. Did anyone tried that?

Cheers,

node v0.8.1
npm 1.1.33
Mac OS X 10.6.8

package.json wants node ~0.6.x so I guess this is not unexpected. Any hints on how to fix this and what else could be broken?

> var leveldb = require('leveldb')
Error: dlopen(/Users/carlos/t76/node_modules/leveldb/lib/leveldb.node, 1): no suitable image found.  Did find:
    /Users/carlos/t76/node_modules/leveldb/lib/leveldb.node: mach-o, but wrong architecture
    at Object.Module._extensions..node (module.js:480:11)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    at Object.<anonymous> (/Users/carlos/t76/node_modules/leveldb/lib/leveldb/handle.js:3:11)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)

Master will always be solid
develop is where in progress work goes

All "real" work on feature branches that are pulled into develop and when develop is ready it is pulled into master and npm published.

npm doesn't install coffee-script if it's already installed locally which leaves
node-leveldb's own node_modules directory empty, causing following postinstall step to fail.

> [email protected] postinstall /Users/don/dev/test/node_modules/leveldb
> ./node_modules/coffee-script/bin/coffee -b -c -o lib/ src

sh: ./node_modules/coffee-script/bin/coffee: No such file or directory

node -v v0.10.1
node-gyp -v v0.8.5
System Darwin 12.3.0

../src/cpp/handle.cc:77:12: error: no matching function for call to 'AsyncQueue'
return AsyncQueue(op, AsyncWorker, AsyncCallback);
^~~~~~~~~~

2 warnings generated.
LIBTOOL-STATIC Release/snappy.a
CXX(target) Release/obj.target/leveldb/src/cpp/batch.o
CXX(target) Release/obj.target/leveldb/src/cpp/binding.o
CXX(target) Release/obj.target/leveldb/src/cpp/comparator.o
CXX(target) Release/obj.target/leveldb/src/cpp/handle.o
../src/cpp/handle.cc:77:12: error: no matching function for call to 'AsyncQueue'
return AsyncQueue(op, AsyncWorker, AsyncCallback);
^~~~~~~~~~
../src/cpp/handle.cc:234:12: note: in instantiation of function template specialization
'node_leveldb::JHandle::OpAsync::AsyncEnqueue<node_leveldb::JHandle::ReadAsync>' requested here
return AsyncEnqueue(op);
^
...

@my8bird posted the following test error:

  ✖ 1 of 41 tests failed:

  1) Iterator db.forRange() should iterate until limit key:

      actual expected

      107

  AssertionError: "107" == ""
      at i (/home/nathan/src/node-leveldb/test/iterator-test.coffee:202:18)
      at exports.Iterator.Iterator.forRange.next (/home/nathan/src/node-leveldb/lib/leveldb/iterator.js:142:9)
      at exports.Iterator.Iterator._wrapSeek (/home/nathan/src/node-leveldb/lib/leveldb/iterator.js:62:28)

I've also been getting intermittent test errors that disappear on the the next run.

@mikepb says:

The tests failures happen randomly. I haven't the time to track down the issue. There's a lot of multithreading involved, that may be the issue.

This param setup seems fishy to me.

https://github.com/my8bird/node-leveldb/blob/master/src/binding/DB.h#L73

With the latest 0.7.1 from npm I'm seing random empty keys when iterating over a database created by an earlier version of node-leveldb on node.js 0.6.x

I think it's unlikely that the database is corrupted, as it is successfully read by the earlier node-leveldb version and by a C++ program using leveldb directly.

The c++ program iterates over 269298 records and doesn't get any empty keys. Same for leveldb 0.5.5 on node.js 0.6.11, with somewhat different code

leveldb 0.7.1 on node 0.8.8 gets 269298 records as well, but between 2 and 7 of them have a empty key. The exact number depends on the run and on what I do while iterating.

It is perfectly possible I'm doing something really stupid so below's the code, unfortunately I can't share the db.
With this code - which just iterates - I get 4 empty keys all the time and always in the same positions: 1661, 6138, 22158, 114237 but that changes just by moving console.log statements around

#!/usr/bin/env node

'use strict'

var leveldb = require('leveldb');

leveldb.open('./encodingDict', {create_if_missing:true}, function(err, db) {
  if(err) {
    return cb(err);
  }

  readEncodingDict(db, function(err) {
    if(err) {
      return cb(err);
    }
    console.log('read OK');
  });
});

var encodingDict = {};

var count = 0;
function readEncodingDict(db, cb) {
  db.iterator(function(err, it) {
    if(err) {
      return cb(err);
    }

    it.first(function(err) {
      if(err) {
        return cb(err);
      }

      function goGet() {
        if(!it.valid()) {
          console.log('read', count, 'records');
                return cb(null);
        }

        it.key(function(err, key) {
          if(err) {
            return cb(err);
          }

          ++count;

          if(key === '') {
            console.log('empty key on position', count);
          }

          it.next(function(err) {
            if(err) {
              return cb(err);
            }
            process.nextTick(goGet);
          });
        });
      }

      goGet();
    });
  });
}

justmoon, mikepb

Since you two seem to be really active and have lots of useful insight into the project I have added you both as collaborators to the GitHub repository. I do not know how this will play out but it should at least making merging changes easier since all git refs will be in the same repository. If either of you do not want to be on the "main" repository for whatever reason just let me know, no hard feelings.

Also, if either of you would like I think npm allows for multiple owners of a project. This would primarily allow you to do npm publish. Of course, we would need to be sure to sync up prior to doing such things so that bug fixes do not collide.

Tried to npm install and got the following:

'build' finished successfully (9m42.136s)> [email protected] postinstall /home/pi/git/bblite/node_modules/leveldb> make pkgclean

coffee --bare --compile --output lib src/coffee
make: coffee: Command not found
make: *** [coffee] Error 127
npm ERR! [email protected] postinstall: make pkgclean

I did a global install coffee-script and this went away.

moon@clymene:/var/www/node-bitcoin-p2p$ sudo npm install leveldb
npm http GET https://registry.npmjs.org/leveldb
npm http 304 https://registry.npmjs.org/leveldb
npm http GET https://registry.npmjs.org/coffee-script
npm http 304 https://registry.npmjs.org/coffee-script

> [email protected] install /atlas/www/node-bitcoin-p2p/node_modules/leveldb
> node-waf configure build

Checking for program g++ or c++          : /usr/bin/g++ 
Checking for program cpp                 : /usr/bin/cpp 
Checking for program ar                  : /usr/bin/ar 
Checking for program ranlib              : /usr/bin/ranlib 
Checking for g++                         : ok  
Checking for program gcc or cc           : /usr/bin/gcc 
Checking for gcc                         : ok  
Checking for node path                   : not found 
Checking for node prefix                 : ok /usr/local 
'configure' finished successfully (0.058s)
Waf: Entering directory `/home/nathan/src/node-leveldb/build'
Waf: Leaving directory `/home/nathan/src/node-leveldb/build'
cp: cannot stat `/home/nathan/src/node-leveldb/build/Release/leveldb.node': No such file or directory
'build' finished successfully (0.007s)

> [email protected] postinstall /atlas/www/node-bitcoin-p2p/node_modules/leveldb
> ./node_modules/coffee-script/bin/coffee -b -c -o lib/ src

[email protected] ./node_modules/leveldb 
└── [email protected]

The fix is to delete the build directory:

moon@clymene:/var/www/node-bitcoin-p2p$ sudo rm -r node_modules/leveldb/build/
moon@clymene:/var/www/node-bitcoin-p2p$ cd node_modules/leveldb/
moon@clymene:/var/www/node-bitcoin-p2p/node_modules/leveldb$ sudo node-waf configure build
Checking for program g++ or c++          : /usr/bin/g++ 
Checking for program cpp                 : /usr/bin/cpp 
Checking for program ar                  : /usr/bin/ar 
Checking for program ranlib              : /usr/bin/ranlib 
Checking for g++                         : ok  
Checking for program gcc or cc           : /usr/bin/gcc 
Checking for gcc                         : ok  
Checking for node path                   : not found 
Checking for node prefix                 : ok /usr/local 
'configure' finished successfully (0.042s)
Waf: Entering directory `/atlas/www/node-bitcoin-p2p/node_modules/leveldb/build'
[ 1/47] cxx: deps/snappy/snappy.cc -> build/Release/deps/snappy/snappy_1.o
[ 2/47] cxx: deps/snappy/snappy-sinksource.cc -> build/Release/deps/snappy/snappy-sinksource_1.o
[...etc...]

You can try changing the .npmignore entry from build to build/, but I've found that even then NPM is pretty wonky about randomly including stuff. My advice is to just make a habit of rm -r build before npm publish.

Reported by email from Paresh Thummar [email protected]

Respected sir,
I want to install leveldb in project(In node.js). I use npm install leveldb command to install it. then i got following error.

ERR! [email protected] preinstall: `git submodule update && node-waf configure build && coffee -b -c -o lib src`
ERR! `cmd "/c" "git submodule update && node-waf configure build && coffee -b -c -o lib src"` failed with 1
ERR! 
ERR! Failed at the [email protected] preinstall script.
ERR! This is most likely a problem with the leveldb package,

What should i do?
please give me exact process to use leveldb in my script.

Thank you,