Memoir of My Dalliances in Scala and the Evolution of Casbah http://github.com/mongodb/casbah Brendan McAdams 10gen, Inc. [email protected] @rit Wednesday, March 14, 2012
Scala • October 2009 ... • Put together NY NoSQL Conference (100+ ppl) • Job Imploded • New Job (Novus Partners), New to Scala • October 2010 ... • Joined 10gen • Fulltime MongoDB Developer, work on Hadoop integration, Casbah & general Scala support as significant portion of my job Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code • Dove Right In: Impulse Control Problem or Good Gut Feeling? Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code • Dove Right In: Impulse Control Problem or Good Gut Feeling? • Akka huge part ... #legendofklang Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code • Dove Right In: Impulse Control Problem or Good Gut Feeling? • Akka huge part ... #legendofklang • Custom formulas, DSLs and other tools Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code • Dove Right In: Impulse Control Problem or Good Gut Feeling? • Akka huge part ... #legendofklang • Custom formulas, DSLs and other tools • Began fiddling with MongoDB tools for interstitial caching layer Wednesday, March 14, 2012
Scala • Big Problems, New Tools needed • For much of it, Java wasn’t the answer • Scala brilliant tool for solving problems • Had read Wampler / Payne, not written code • Dove Right In: Impulse Control Problem or Good Gut Feeling? • Akka huge part ... #legendofklang • Custom formulas, DSLs and other tools • Began fiddling with MongoDB tools for interstitial caching layer • Rose Toomey (@prasinous) took it all and ran with it early on... Things snowballed. Wednesday, March 14, 2012
to” ‘mongo-scala-wrappers’ Is Born • Learned MongoDB from Python • Dynamic language with flexible syntax; Dynamic database with flexible schemas Wednesday, March 14, 2012
to” ‘mongo-scala-wrappers’ Is Born • Learned MongoDB from Python • Dynamic language with flexible syntax; Dynamic database with flexible schemas • Tooling for MongoDB + Scala was limited or unsuited. Mostly focused on ODM. None of what I loved about Scala or MongoDB possible together. Wednesday, March 14, 2012
to” ‘mongo-scala-wrappers’ Is Born • Learned MongoDB from Python • Dynamic language with flexible syntax; Dynamic database with flexible schemas • Tooling for MongoDB + Scala was limited or unsuited. Mostly focused on ODM. None of what I loved about Scala or MongoDB possible together. • Java Driver ... No Scala sugar or tricks Wednesday, March 14, 2012
to” ‘mongo-scala-wrappers’ Is Born • Learned MongoDB from Python • Dynamic language with flexible syntax; Dynamic database with flexible schemas • Tooling for MongoDB + Scala was limited or unsuited. Mostly focused on ODM. None of what I loved about Scala or MongoDB possible together. • Java Driver ... No Scala sugar or tricks • scamongo (pre-lift): ODM (ORMey) or JSON tools Wednesday, March 14, 2012
to” ‘mongo-scala-wrappers’ Is Born • Learned MongoDB from Python • Dynamic language with flexible syntax; Dynamic database with flexible schemas • Tooling for MongoDB + Scala was limited or unsuited. Mostly focused on ODM. None of what I loved about Scala or MongoDB possible together. • Java Driver ... No Scala sugar or tricks • scamongo (pre-lift): ODM (ORMey) or JSON tools • mongo-scala-driver: A little syntactic sugar but mostly ODM; didn’t “get” it Wednesday, March 14, 2012
absolutely nothing wrong with that Syntax... For Java. • Scala is expressive, fluid and beautiful; so is (IMHO) MongoDB. • My goal: Teach Scala to be as close to Python / Mongo Shell as possible Wednesday, March 14, 2012
absolutely nothing wrong with that Syntax... For Java. • Scala is expressive, fluid and beautiful; so is (IMHO) MongoDB. • My goal: Teach Scala to be as close to Python / Mongo Shell as possible • Self Imposed Limitation: Don’t reinvent the wheel. Java Driver’s Network Layers, BSON Encoding, etc work great. Wednesday, March 14, 2012
absolutely nothing wrong with that Syntax... For Java. • Scala is expressive, fluid and beautiful; so is (IMHO) MongoDB. • My goal: Teach Scala to be as close to Python / Mongo Shell as possible • Self Imposed Limitation: Don’t reinvent the wheel. Java Driver’s Network Layers, BSON Encoding, etc work great. • Just add Syntactic Sugar! Wednesday, March 14, 2012
= MongoConnection()("casbahTest") val coll = db("test_coll_%d".format(System.currentTimeMillis)) for (i <- 1 to 100) coll += MongoDBObject("foo" -> "bar", "x" -> Random.nextDouble()) val first5 = coll.find(MongoDBObject("foo" -> "bar")) limit 5 "Behave in chains" in { "Chain operations must return the proper *subtype*" in { val cur = coll.find(MongoDBObject("foo" -> "bar")) skip 5 cur must haveClass[MongoCursor] val cur2 = coll.find(MongoDBObject("foo" -> "bar")) limit 25 skip 12 cur2 must haveClass[MongoCursor] } } } Wednesday, March 14, 2012
Feb. 12, 2010: Initial Open Source Release (0.1) No Tests. - Initial import Compiles, reflects the working code currently in Novus Trunk but does not have full documentation, or tests yet. NOT FOR PUBLIC CONSUMPTION - USE AT YOUR OWN RISK. * Release 0.1 - May or may not blow your system up... - Updated headers, scaladoc/javadoc documentation, etc. - Next step: Written docs with examples, test classes • July 17, 2010: Release 1.0. • New collaborator/contributor Max Afonov (@max4f) • January 03, 2011: Release 2.0. • Refactoring & Stupidity cleanups. •Today - Solid, stable, robust & used in several large organizations for production code. • Finishing Casbah 3.0 which is a major cleanup, sanity refactoring and performance boost release • Milestone 2 (“org.mongodb” %% “casbah” % “3.0.0-M2”) currently available Wednesday, March 14, 2012
2 * Hacky mildly absurd method for converting a <code>Product</code> (Example being any <code>Tuple</ code>) to 3 * a Mongo <code>DBObject</code> on the fly to minimize spaghetti code from long builds of Maps or DBObjects. 4 * 5 * Intended to facilitate fluid code but may be dangerous. 6 * _ * SNIP 17 */ 18 implicit def productToMongoDBObject(p: Product): DBObject = { 19 val builder = BasicDBObjectBuilder.start 20 val arityRange = 0.until(p.productArity) 21 //println("Converting Product P %s with an Arity range of %s to a MongoDB Object".format(p, arityRange)) 22 for (i <- arityRange) { 23 val x = p.productElement(i) 24 //println("\tI: %s X: %s".format(i, x)) 25 if (x.isInstanceOf[Tuple2[_,_]]) { 26 val t = x.asInstanceOf[Tuple2[String, Any]] 27 //println("\t\tT: %s".format(t)) 28 builder.add(t._1, t._2) 29 } else if (p.productArity == 2 && p.productElement(0).isInstanceOf[String]) { 30 // backup plan if it's a one entry tuple, the outer wrapper gets stripped 32 val t = p.asInstanceOf[Tuple2[String, Any]] 32 builder.add(t._1, t._2) 33 return builder.get 34 } else { 35 throw new IllegalArgumentException("Products to convert to DBObject must contain Tuple2's.") 36 } 37 } 38 builder.get 39 } 40 Wednesday, March 14, 2012
Classes, Abstract & Parameterized Types (Scala’s variant, esp. with Covariance/Contravariance annotation), Structural (aka “sort of a duck” typing) are incredible Wednesday, March 14, 2012
Classes, Abstract & Parameterized Types (Scala’s variant, esp. with Covariance/Contravariance annotation), Structural (aka “sort of a duck” typing) are incredible • I’ve (conceitedly) evolved 3 Laws of Library Design ... • “Am I helping my users or hurting them?”* Wednesday, March 14, 2012
Classes, Abstract & Parameterized Types (Scala’s variant, esp. with Covariance/Contravariance annotation), Structural (aka “sort of a duck” typing) are incredible • I’ve (conceitedly) evolved 3 Laws of Library Design ... • “Am I helping my users or hurting them?”* • “Have I accounted for all the use cases?” Wednesday, March 14, 2012
Classes, Abstract & Parameterized Types (Scala’s variant, esp. with Covariance/Contravariance annotation), Structural (aka “sort of a duck” typing) are incredible • I’ve (conceitedly) evolved 3 Laws of Library Design ... • “Am I helping my users or hurting them?”* • “Have I accounted for all the use cases?” • “Do I have any idea what the f$%k I’m doing?” Wednesday, March 14, 2012
Much of what I love about Scala are often compile time checks and don’t keep you from misunderstanding things, hurting your users or just plain screwing up. ...then again, I’m no carpenter Wednesday, March 14, 2012
Much of what I love about Scala are often compile time checks and don’t keep you from misunderstanding things, hurting your users or just plain screwing up. • Fun with Type Inference aka “Oops, I screwed the explicit annotators” ...then again, I’m no carpenter Wednesday, March 14, 2012
Much of what I love about Scala are often compile time checks and don’t keep you from misunderstanding things, hurting your users or just plain screwing up. • Fun with Type Inference aka “Oops, I screwed the explicit annotators” • Know and understand the “fancy” features, but also know when to use them. ...then again, I’m no carpenter Wednesday, March 14, 2012
Much of what I love about Scala are often compile time checks and don’t keep you from misunderstanding things, hurting your users or just plain screwing up. • Fun with Type Inference aka “Oops, I screwed the explicit annotators” • Know and understand the “fancy” features, but also know when to use them. “The difference between a junior and a senior programmer is oſten that the senior has the wisdom to know when not to write code.” ...then again, I’m no carpenter Wednesday, March 14, 2012
safety /** * I had used Type classes elsewhere, but when I posted the preceding * manifest code as an example of cool stuff to show @ ScalaDays, * Jon-Anders Teigen (@jteigen) sent me a gist with a better way. * Type Classes for this! */ def $type[A](implicit bsonType: BSONType[A]) = op(oper, bsonType.operator) /** * Thats now it for the $type support, it uses a few type class definitions as * well to match the BSON types. */ implicit object BSONDouble extends BSONType[Double](BSON.NUMBER) implicit object BSONString extends BSONType[String](BSON.STRING) implicit object BSONObject extends BSONType[BSONObject](BSON.OBJECT) implicit object DBObject extends BSONType[DBObject](BSON.OBJECT) implicit object DBList extends BSONType[BasicDBList](BSON.ARRAY) implicit object BSONDBList extends BSONType[BasicBSONList](BSON.ARRAY) implicit object BSONBinary extends BSONType[Array[Byte]](BSON.BINARY) implicit object BSONObjectId extends BSONType[ObjectId](BSON.OID) implicit object BSONBoolean extends BSONType[Boolean](BSON.BOOLEAN) implicit object BSONJDKDate extends BSONType[java.util.Date](BSON.DATE) implicit object BSONJodaDateTime extends BSONType[org.joda.time.DateTime](BSON.DATE) implicit object BSONNull extends BSONType[Option[Nothing]](BSON.NULL) implicit object BSONRegex extends BSONType[Regex](BSON.REGEX) implicit object BSONSymbol extends BSONType[Symbol](BSON.SYMBOL) implicit object BSON32BitInt extends BSONType[Int](BSON.NUMBER_INT) implicit object BSON64BitInt extends BSONType[Long](BSON.NUMBER_LONG) implicit object BSONSQLTimestamp extends BSONType[java.sql.Timestamp](BSON.TIMESTAMP) Wednesday, March 14, 2012
you skip over certain implicit arguments: def $type[A: BSONType: Manifest] • Is the equivalent of coding: def $type[A](implicit evidence$1: BSONType[A],implicit evidence$2: Manifest[A]) Wednesday, March 14, 2012
def insert[A <% DBObject](docs: Traversable[A], writeConcern: WriteConcern) = { val b = new scala.collection.mutable.ArrayBuilder.ofRef[DBObject] b.sizeHint(docs.size) for (x <- docs) b += x underlying.insert(b.result, writeConcern) } Wednesday, March 14, 2012
def insert[A <% DBObject](docs: Traversable[A], writeConcern: WriteConcern) = { val b = new scala.collection.mutable.ArrayBuilder.ofRef[DBObject] b.sizeHint(docs.size) for (x <- docs) b += x underlying.insert(b.result, writeConcern) } • Answer: This is a “View Boundary” Wednesday, March 14, 2012
def insert[A <% DBObject](docs: Traversable[A], writeConcern: WriteConcern) = { val b = new scala.collection.mutable.ArrayBuilder.ofRef[DBObject] b.sizeHint(docs.size) for (x <- docs) b += x underlying.insert(b.result, writeConcern) } • Answer: This is a “View Boundary” • Code “flattens” at compile time to something like this: def insert[A](docs: Traversable[A], writeConcern: WriteConcern) (implicit ev: A => DBObject) = { val b = new scala.collection.mutable.ArrayBuilder.ofRef[DBObject] b.sizeHint(docs.size) for (x <- docs) b += ev(x) underlying.insert(b.result, writeConcern) } Wednesday, March 14, 2012
I accepted a pull request from Jon-Anders Teigen (@jteigen) which applies a clever trick he learned from Miles Sabin (@milessabin) Wednesday, March 14, 2012
I accepted a pull request from Jon-Anders Teigen (@jteigen) which applies a clever trick he learned from Miles Sabin (@milessabin) • Manifests are great for type safety, but sort of sucks when the type parameter isn’t populated and violations only appear at runtime Wednesday, March 14, 2012
I accepted a pull request from Jon-Anders Teigen (@jteigen) which applies a clever trick he learned from Miles Sabin (@milessabin) • Manifests are great for type safety, but sort of sucks when the type parameter isn’t populated and violations only appear at runtime Wednesday, March 14, 2012
I accepted a pull request from Jon-Anders Teigen (@jteigen) which applies a clever trick he learned from Miles Sabin (@milessabin) • Manifests are great for type safety, but sort of sucks when the type parameter isn’t populated and violations only appear at runtime • From an early feature request, Casbah has long had a getAs[T] method to simplify the casting nonsense when working with a network populated Map[String, Any] Wednesday, March 14, 2012
without conflicting with Map's required get() method and causing ambiguity */ def getAs[A <: Any: Manifest](key: String): Option[A] = { require(manifest[A] != manifest[scala.Nothing], "Type inference failed; getAs[A]() requires an explicit type argument " + "(e.g. dbObject.getAs[<ReturnType>](\"somegetAKey\") ) to function correctly.") underlying.get(key) match { case null => None case value => Some(value.asInstanceOf[A]) } } // Test for "fail when no type is specified" dbObj.getAs("x") must throwA[IllegalArgumentException] Wednesday, March 14, 2012
using ambiguity in implicit resolution to disallow Nothing */ sealed trait NotNothing[A]{ type B } object NotNothing { implicit val nothing = new NotNothing[Nothing]{ type B = Any } implicit def notNothing[A] = new NotNothing[A]{ type B = A } } /** Lazy utility method to allow typing without conflicting with Map's required get() method and causing ambiguity */ def getAs[A : NotNothing](key: String): Option[A] = { underlying.get(key) match { case null => None case value => Some(value.asInstanceOf[A]) } } Wednesday, March 14, 2012
01, 2010: The death of “mongo-scala-wrappers” - Changed package to com.novus.casbah.mongodb - Rolled Scala version to 2.8.0.RC3 and SBT version to 0.7.4 - Updated dependency libraries as appropriate for 2.8rc3 - Cleaned up package declarations in code - Rolled module version to 1.0-SNAPSHOT as the next release goal is to be complete at a 1.0 • Time for a name change • Users and colleagues felt we’d grown beyond simply “wrappers” for the Java driver • Name was still fairly similar to mongo-scala-driver; observed confusion Wednesday, March 14, 2012
mostly randomly from The Clash • 1.1 Began on a mission of modularisation and functionality expansion • “casbah-mapper” borne unto git, never released mainstream and ultimately reimagined as “Salat” (Russian word салат for “salad”) Wednesday, March 14, 2012
mostly randomly from The Clash • 1.1 Began on a mission of modularisation and functionality expansion • “casbah-mapper” borne unto git, never released mainstream and ultimately reimagined as “Salat” (Russian word салат for “salad”) • salat-avro (@rubbish from T8Webware) Wednesday, March 14, 2012
mostly randomly from The Clash • 1.1 Began on a mission of modularisation and functionality expansion • “casbah-mapper” borne unto git, never released mainstream and ultimately reimagined as “Salat” (Russian word салат for “salad”) • salat-avro (@rubbish from T8Webware) • @coda’s “Jerkson” project using some of the ScalaSig code utils from Salat Wednesday, March 14, 2012
It Palatable” • There’s a difference between “Fixing bugs in production” and “Shipping libraries to users” • Eating my own dog food was great, but in many ways it made me complacent Wednesday, March 14, 2012
It Palatable” • There’s a difference between “Fixing bugs in production” and “Shipping libraries to users” • Eating my own dog food was great, but in many ways it made me complacent • In many cases I initially only implemented MongoDB features I was using... Wednesday, March 14, 2012
It Palatable” • There’s a difference between “Fixing bugs in production” and “Shipping libraries to users” • Eating my own dog food was great, but in many ways it made me complacent • In many cases I initially only implemented MongoDB features I was using... • ... In others, only the way I was using them. Wednesday, March 14, 2012
It Palatable” • 15 years as a developer taught me this: “Tests seem like a really good idea... I’m tired of fixing my broken crap in production” for (i <- 1 to ∞) println(“Tests. Matter.”) Wednesday, March 14, 2012
It Palatable” • 15 years of reality tempered “nice to have” with “shutup and code, monkey”: <Me> “Our code keeps breaking in production. We should take the time to write tests” ... or ... “Our tests suck. We should take the time to learn how to write good tests.” <Boss> “Just put it in production and fix it later, we don’t have time to wait” Wednesday, March 14, 2012
It Palatable” • 15 years of reality tempered “nice to have” with “shutup and code, monkey”: <Me> “Our code keeps breaking in production. We should take the time to write tests” ... or ... “Our tests suck. We should take the time to learn how to write good tests.” <Boss> “Just put it in production and fix it later, we don’t have time to wait” • Let’s face it: This isn’t an excuse but in many cases, reality. Unless you're a sheltered academic, you either ship code or start an exciting new career flipping burgers. Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala • ScalaTest (I don’t use anymore but still amazing) * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala • ScalaTest (I don’t use anymore but still amazing) • Specs / Specs 2: Alien Technology for breaking my code * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala • ScalaTest (I don’t use anymore but still amazing) • Specs / Specs 2: Alien Technology for breaking my code • ScalaCheck - Haven’t learned it yet, but does fuzzing, etc * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala • ScalaTest (I don’t use anymore but still amazing) • Specs / Specs 2: Alien Technology for breaking my code • ScalaCheck - Haven’t learned it yet, but does fuzzing, etc • Differentiate between integration tests and unit tests * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • If you plan to ship code to users, “eating your own dog food” is NEVER ENOUGH* • Take the time to learn how to write good tests and GOOD DATA • I am head over heels in love with the tools in Scala • ScalaTest (I don’t use anymore but still amazing) • Specs / Specs 2: Alien Technology for breaking my code • ScalaCheck - Haven’t learned it yet, but does fuzzing, etc • Differentiate between integration tests and unit tests • But *use* integration tests with “conditional skips”, and WRITE THEM. * Assuming of course you care about code quality and/or your users Wednesday, March 14, 2012
It Palatable” • Some of why I didn’t test Casbah as well early on is I couldn’t easily test the values as MongoDB saw them. • With moving to Specs2, it was much more strict and I was inspired to write custom matchers to do the job; provided for users too! (Tests all the way down...) Wednesday, March 14, 2012
It Palatable” • Some of why I didn’t test Casbah as well early on is I couldn’t easily test the values as MongoDB saw them. • With moving to Specs2, it was much more strict and I was inspired to write custom matchers to do the job; provided for users too! (Tests all the way down...) • Tests are much cleaner and I feel more confident about them; able to achieve higher coverage Wednesday, March 14, 2012
It Palatable” • Some of why I didn’t test Casbah as well early on is I couldn’t easily test the values as MongoDB saw them. • With moving to Specs2, it was much more strict and I was inspired to write custom matchers to do the job; provided for users too! (Tests all the way down...) • Tests are much cleaner and I feel more confident about them; able to achieve higher coverage • Higher coverage definitively relates to less bugs users find in their production apps Wednesday, March 14, 2012
contains a pair (key, value) == (k, v) * Will expand out dot notation for matching. **/ def haveSomeEntry[V](p: (String, V)) = new Matcher[Option[DBObject]] { def apply[S <: Option[DBObject]](map: Expectable[S]) = { result(someField(map, p._1).exists(_ == p._2), // match only the value map.description + " has the pair " + p, map.description + " doesn't have the pair " + p, map) } } /** Special version of "HaveEntry" that expects a list and then uses * "hasSameElements" on it. */ def haveListEntry(k: String, l: => Traversable[Any]) = new Matcher[DBObject] { def apply[S <: DBObject](map: Expectable[S]) = { val objL = listField(map, k).getOrElse(Seq.empty[Any]).toSeq val _l = l.toSeq result(objL.sameElements(_l), // match only the value map.description + " has the pair " + k, map.description + " doesn't have the pair " + k, map) } } /** matches if map contains a pair (key, value) == (k, v) * Will expand out dot notation for matching. **/ def haveEntry[V](p: (String, V)) = new Matcher[DBObject] { def apply[S <: DBObject](map: Expectable[S]) = { result(field(map, p._1).exists(_.equals(p._2)), // match only the value map.description + " has the pair " + p, map.description + "[" + field(map, p._1) + "] doesn't have the pair " + p + "[" + p._2 + "]", map) } } /** matches if Some(map) contains all the specified pairs * can expand dot notation to match specific sub-keys */ def haveSomeEntries[V](pairs: (String, V)*) = new Matcher[Option[DBObject]] { def apply[S <: Option[DBObject]](map: Expectable[S]) = { result(pairs.forall(pair => someField(map, pair._1).exists(_ == pair._2) /* match only the value */ ), map.description + " has the pairs " + pairs.mkString(", "), map.description + " doesn't have the pairs " + pairs.mkString(", "), map) } } /** matches if map contains all the specified pairs * can expand dot notation to match specific sub-keys */ def haveEntries[V](pairs: (String, V)*) = new Matcher[DBObject] { def apply[S <: DBObject](map: Expectable[S]) = { result(pairs.forall(pair => field(map, pair._1).exists(_ == pair._2) /* match only the value */ ), map.description + " has the pairs " + pairs.mkString(", "), map.description + " doesn't have the pairs " + pairs.mkString(", "), map) } } } Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO • NOT (contrary to popular panic/confusion) a replacement for Casbah Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO • NOT (contrary to popular panic/confusion) a replacement for Casbah • Focused more on framework support than userspace Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO • NOT (contrary to popular panic/confusion) a replacement for Casbah • Focused more on framework support than userspace • Will likely offer optional synchronous and asynchronous hammersmith module for casbah-core, with Java driver as casbah- core-classic Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO • NOT (contrary to popular panic/confusion) a replacement for Casbah • Focused more on framework support than userspace • Will likely offer optional synchronous and asynchronous hammersmith module for casbah-core, with Java driver as casbah- core-classic • Working on sharing as much code as possible between Hammersmith & Casbah for MongoDBObject, etc. Wednesday, March 14, 2012
but it also has a younger brother/cousin • “Hammersmith”, purely asynchronous, purely Scala and a distillation of ~2 years of MongoDB knowledge • Only Java is the BSON serialization; still no excuse for reinventing the wheel • Netty for now, but probably will end up as pure NIO • NOT (contrary to popular panic/confusion) a replacement for Casbah • Focused more on framework support than userspace • Will likely offer optional synchronous and asynchronous hammersmith module for casbah-core, with Java driver as casbah- core-classic • Working on sharing as much code as possible between Hammersmith & Casbah for MongoDBObject, etc. • Porting casbah-query to target Hammersmith (as well as Lift) Wednesday, March 14, 2012
you want to be serialized or deserialized */ trait SerializableBSONObject[T] { def encode(doc: T, out: OutputBuffer) def encode(doc: T): Array[Byte] def decode(in: InputStream): T def decode(bytes: Seq[Array[Byte]]): Seq[T] = for (b <- bytes) yield decode(b) def decode(b: Array[Byte]): T = decode(new ByteArrayInputStream(b)) /** * These methods are used to validate documents in certain cases. * They will be invoked by the system at the appropriate times and you must * implement them in a manner appropriate for your object to ensure proper mongo saving. */ def checkObject(doc: T, isQuery: Boolean = false): Unit def checkKeys(doc: T): Unit /** * Checks for an ID and generates one, returning a new doc with the id. * The new doc may be a mutation of the old doc, OR a new object * if the old doc was immutable. */ def checkID(doc: T): T def _id(doc: T): Option[AnyRef] } Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async • Integration with Lift, Salat, etc. Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async • Integration with Lift, Salat, etc. • Tests & Documentation! Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async • Integration with Lift, Salat, etc. • Tests & Documentation! • <insert your brilliant idea here> Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async • Integration with Lift, Salat, etc. • Tests & Documentation! • <insert your brilliant idea here> • Ditto for Casbah! (More code, Lift Integration, Documentation, etc) Wednesday, March 14, 2012
project, which means it only gets love when I have time or some people contribute • A few great users like Havoc Pennington (@havocp), Rose Toomey (@prasinous) and Gerolf Seitz (@gersei) have taken some time to contribute and get involved • ... but, like me, they get busy • This could be a truly fantastic tool and it is a blast to develop on • Things being worked on that need help • Porting core to Akka, using Actors to coordinate async infrastructure without risk of stupid users blocking • Delimited Continuations based “synchronous” appearing API; users think they’re writing sync code but get true async • Integration with Lift, Salat, etc. • Tests & Documentation! • <insert your brilliant idea here> • Ditto for Casbah! (More code, Lift Integration, Documentation, etc) • Fork it and get involved! Wednesday, March 14, 2012
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bkuhlmann
estie
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sonatard
marxallski
tomokusaba
seyfoyun
karad
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mza
rocio
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holman
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keathley
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