Objective-C view support for Couchbase Mobile iOS

This is a squashed commit of all the work done on other
branches by Jonathon Mah & me.

Change-Id: I0b9d020d57502b2ea46b695d9788e42ceb7225fb
Reviewed-on: http://review.couchbase.org/10023
Reviewed-by: Jonathon Mah <me@jonathonmah.com>
Reviewed-by: Chris Anderson <jchris@couchbase.com>
Tested-by: Jens Alfke <jens@couchbase.com>

src/couchdb/couch_app_server_objc.erl

@@ -0,0 +1,50 @@
+% Licensed 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.
+
+-module(couch_app_server_objc).
+
+-export([get_server/3, ret_server/1]).
+-export([show_doc/5, validate_update/6, filter_docs/5, filter_view/4]).
+-export([list_start/5, list_row/3, list_end/2, update_doc/5]).
+
+-include("couch_db.hrl").
+
+get_server(_Arg, DDoc, DDocKey) ->
+    objc_dispatch:app_create(DDoc, DDocKey).
+
+ret_server(_) ->
+    ok.
+
+show_doc(Ctx, DDocId, ShowName, Doc, Req) ->
+    objc_dispatch:app_show_doc(Ctx, DDocId, ShowName, Doc, Req).
+
+list_start(Ctx, DDocId, ListName, Head, Req) ->
+    {message, [Chunks, Resp]} = objc_dispatch:app_list_start(Ctx, DDocId, ListName, Head, Req),
+    {ok, Chunks, Resp}.
+
+list_row(Ctx, DDocId, Row) ->
+    objc_dispatch:app_list_row(Ctx, DDocId, Row).
+
+list_end(Ctx, DDocId) ->
+    objc_dispatch:app_list_end(Ctx, DDocId).
+
+update_doc(Ctx, DDocId, UpdateName, Doc, Req) ->
+    objc_dispatch:app_update_doc(Ctx, DDocId, UpdateName, Doc, Req).
+
+validate_update(Ctx, DDocId, EditDoc, DiskDoc, Context, SecObj) ->
+    objc_dispatch:app_validate_update(Ctx, DDocId, EditDoc, DiskDoc, Context, SecObj).
+
+filter_docs(Ctx, DDocId, FilterName, Docs, Req) ->
+    objc_dispatch:app_filter_docs(Ctx, DDocId, FilterName, Docs, Req).
+
+filter_view(Ctx, DDocId, ViewName, Docs) ->
+    objc_dispatch:app_filter_view(Ctx, DDocId, ViewName, Docs).

src/couchdb/couch_view_server_objc.erl

@@ -0,0 +1,71 @@
+% Licensed 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.
+-module(couch_view_server_objc).
+
+-export([is_lightweight/0, add_view_deps/1]).
+-export([get_server/3, ret_server/1]).
+-export([map/2, reduce/3, rereduce/3]).
+
+-include("couch_db.hrl").
+
+is_lightweight() ->
+    true.
+
+add_view_deps(View) ->
+    % Catch any error here; we don't really care what it is, only
+    % that there is an error (so we don't correspond to any other
+    % pre-computed views). The underlying error will be hit when
+    % (and if) the view is actually built.
+    ObjCVers = try objc_dispatch:query_view_version(View#view.def)
+    catch
+        _ -> error
+    end,
+    [View, ObjCVers].
+
+get_server(_Arg, Maps, ReduceStruct) ->
+    % ReduceStruct is [[ViewId, [RedDef, ...]], [ViewId, [...], ...].
+    % Turn this into [RedDef, ...] to decode, and a map of [{ViewId, [3, 4]}, ...]
+    % where [3,4] are indexes (0-based) into the array of RedDefs.
+    {RevIndexMap, RevAllRedDefs, _} = lists:foldl(fun([ViewId, RedDefs], {IdIndexAssoc, RedDefAcc, NextIndex}) ->
+        {NewRedDefs, Indexes, NewNextIndex} = lists:foldl(fun(RedDef, {RedDefs, Indexes, Index}) ->
+            {[RedDef | RedDefs], [Index | Indexes], Index + 1}
+        end, {RedDefAcc, [], NextIndex}, RedDefs),
+        {[{ViewId, Indexes} | IdIndexAssoc], NewRedDefs, NewNextIndex}
+    end, {[], [], 0}, ReduceStruct),
+    AllRedDefs = lists:reverse(RevAllRedDefs),
+    RedIndexMap = [{ViewId, lists:reverse(RevIndexes)} || {ViewId, RevIndexes} <- RevIndexMap],
+    {ok, QueueRef} = objc_dispatch:create(<<"org.couchdb.objc_view">>, Maps, AllRedDefs),
+    {ok, {QueueRef, RedIndexMap}}.
+
+ret_server(_) ->
+    ok.
+
+map({QueueRef, _RedIndexMap}, Docs) ->
+    Results = lists:map(fun(Doc) ->
+        JsonDoc = couch_doc:to_json_obj(Doc, []),
+        {ok, EmitsPerView} = objc_dispatch:map(QueueRef, JsonDoc),
+        lists:map(fun(EmitListItem) ->
+            [list_to_tuple(EmitPair) || EmitPair <- EmitListItem]
+        end, EmitsPerView)
+    end, Docs),
+    {ok, Results}.
+
+reduce({QueueRef, RedIndexMap}, ViewId, KVs) ->
+    Indexes = proplists:get_value(ViewId, RedIndexMap),
+    {Keys, Vals} = lists:foldl(fun([K, V], {KAcc, VAcc}) ->
+        {[K | KAcc], [V | VAcc]}
+    end, {[], []}, KVs),
+    objc_dispatch:reduce(QueueRef, Indexes, Keys, Vals, false).
+
+rereduce({QueueRef, RedIndexMap}, ViewId, Vals) ->
+    Indexes = proplists:get_value(ViewId, RedIndexMap),
+    objc_dispatch:reduce(QueueRef, Indexes, null, Vals, true).

src/objc-dispatch/c_src/CouchbaseAppServer.h

@@ -0,0 +1,30 @@
+//
+//  CouchbaseAppServer.h
+//  iErl14
+//
+//  Created by Jens Alfke on 10/6/11.
+//  Copyright (c) 2011 Couchbase, Inc. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import "CouchbaseCallbacks.h"
+#include "erl_nif.h"
+
+@interface CouchbaseAppServer : NSObject
+{
+    ErlNifEnv* _env;
+    NSDictionary* _designDoc;
+    CouchValidateUpdateBlock _validateUpdateBlock;
+}
+
+- (id) initWithDesignDoc: (NSDictionary*)designDoc;
+
+@property ErlNifEnv* env;
+
+- (BOOL) validateUpdate: (ERL_NIF_TERM)updatedDoc
+             ofDocument: (ERL_NIF_TERM)currentRevision
+                context: (ERL_NIF_TERM)context
+               security: (ERL_NIF_TERM)security
+                  error: (NSDictionary**)outError;
+
+@end

src/objc-dispatch/c_src/CouchbaseAppServer.m

@@ -0,0 +1,156 @@
+//
+//  CouchbaseAppServer.m
+//  iErl14
+//
+//  Created by Jens Alfke on 10/6/11.
+//  Copyright (c) 2011 Couchbase, Inc. All rights reserved.
+//
+
+#import "CouchbaseAppServer.h"
+#import "term_to_objc.h"
+
+
+@interface CouchbaseValidationContext : NSObject <CouchbaseValidationContext>
+{
+    @private
+    ErlNifEnv* _env;
+    ERL_NIF_TERM _currentRevisionTerm, _contextTerm, _securityTerm;
+    NSDictionary* _currentRevision;
+    NSDictionary* _contextDict;
+    NSDictionary* _security;
+    NSString* _errorType, *_errorMessage;
+}
+- (id) initWithEnv: (ErlNifEnv*)env
+   currentRevision: (ERL_NIF_TERM)currentRevision
+           context: (ERL_NIF_TERM)context
+          security: (ERL_NIF_TERM)security;
+@end
+
+
+@implementation CouchbaseAppServer
+
+- (id) initWithDesignDoc: (NSDictionary*)designDoc {
+    self = [super init];
+    if (self) {
+        NSParameterAssert(designDoc);
+        _designDoc = [designDoc copy];
+    }
+    return self;
+}
+
+- (void)dealloc {
+    [_validateUpdateBlock release];
+    [_designDoc release];
+    [super dealloc];
+}
+
+
+@synthesize env = _env;
+
+
+- (BOOL) validateUpdate: (ERL_NIF_TERM)documentTerm
+             ofDocument: (ERL_NIF_TERM)currentRevisionTerm
+                context: (ERL_NIF_TERM)contextTerm
+               security: (ERL_NIF_TERM)securityTerm
+                  error: (NSDictionary**)outError
+{
+    if (!_validateUpdateBlock) {
+        NSString* key = [_designDoc objectForKey: @"validate_doc_update"];
+        if ([key isKindOfClass: [NSString class]])
+            _validateUpdateBlock = [[[CouchbaseCallbacks sharedInstance]
+                                        validateUpdateBlockForKey: key] copy];
+
+        if (!_validateUpdateBlock)
+            [NSException raise: NSInternalInconsistencyException
+                        format: @"Unregistered native validate_doc_update function '%@'", key];
+    }
+
+    NSDictionary* document = term_to_nsdict(_env, documentTerm);
+    if (!document)
+        return NO;
+
+    CouchbaseValidationContext* context = [[CouchbaseValidationContext alloc]
+                                                              initWithEnv: _env
+                                                          currentRevision: currentRevisionTerm
+                                                                  context: contextTerm
+                                                                 security: securityTerm];
+    [context autorelease];
+
+    if (_validateUpdateBlock(document, context))
+        return YES;
+
+    *outError = [NSDictionary dictionaryWithObject: context.errorMessage forKey: context.errorType];
+    NSLog(@"Doc failed validation with error {%@: %@}", context.errorType, context.errorMessage);
+    return NO;
+}
+
+@end
+
+
+
+@implementation CouchbaseValidationContext
+
+
+- (id) initWithEnv: (ErlNifEnv*)env
+   currentRevision: (ERL_NIF_TERM)currentRevision
+           context: (ERL_NIF_TERM)context
+          security: (ERL_NIF_TERM)security
+{
+    self = [super init];
+    if (self) {
+        NSParameterAssert(env);
+        _env = env;
+        _currentRevisionTerm = currentRevision;
+        _contextTerm = context;
+        _securityTerm = security;
+        _errorType = [@"forbidden" retain];
+        _errorMessage = [@"invalid document" retain];
+    }
+    return self;
+}
+
+- (void)dealloc {
+    [_errorType release];
+    [_errorMessage release];
+    [_currentRevision release];
+    [_contextDict release];
+    [_security release];
+    [super dealloc];
+}
+
+- (NSDictionary*) currentRevision {
+    if (!_currentRevision)
+        _currentRevision = [term_to_nsdict(_env, _currentRevisionTerm) retain];
+    return _currentRevision;
+}
+
+- (NSDictionary*) contextDict {
+    if (!_contextDict)
+        _contextDict = [term_to_nsdict(_env, _contextTerm) retain];
+    return _contextDict;
+}
+
+- (NSString*) databaseName {
+    return [self.contextDict objectForKey: @"db"];
+}
+
+- (NSString*) userName {
+    id user = [self.contextDict objectForKey: @"name"];
+    if (![user isKindOfClass: [NSString class]])    // anonymous user will be a NSNull object
+        return nil;
+    return user;
+}
+
+- (BOOL) isAdmin {
+    return [[self.contextDict objectForKey: @"roles"] containsObject: @"_admin"];
+}
+
+- (NSDictionary*) security {
+    if (!_security)
+        _security = [term_to_nsdict(_env, _securityTerm) retain];
+    return _security;
+}
+
+@synthesize errorType = _errorType, errorMessage = _errorMessage;
+
+@end

src/objc-dispatch/c_src/CouchbaseCallbacks.h

@@ -0,0 +1,84 @@
+//
+//  CouchbaseCallbacks.h
+//  iErl14
+//
+//  Created by Jens Alfke on 10/3/11.
+//  Copyright (c) 2011 Couchbase, Inc. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+@protocol CouchbaseValidationContext;
+
+
+typedef void (^CouchEmitBlock)(id key, id value);
+
+/** A "map" function called when a document is to be added to a view.
+    @param doc  The contents of the document being analyzed.
+    @param emit  A block to be called to add a key/value pair to the view. Your block can call zero, one or multiple times. */
+typedef void (^CouchMapBlock)(NSDictionary* doc, CouchEmitBlock emit);
+
+/** A "reduce" function called to summarize the results of a view.
+    @param keys  An array of keys to be reduced.
+    @param values  A parallel array of values to be reduced, corresponding one-to-one with the keys.
+    @param rereduce  YES if the input keys and values are the results of previous reductions.
+    @return  The reduced value; almost always a scalar or small fixed-size object. */
+typedef id (^CouchReduceBlock)(NSArray* keys, NSArray* values, BOOL rereduce);
+
+/** Called to validate a document before it's added to the database.
+    @param doc  The submitted document contents.
+    @param context  Lets the block access relevant information and specify an error message.
+    @return  YES to accept the document, NO to reject it. */
+typedef BOOL (^CouchValidateUpdateBlock)(NSDictionary* doc,
+                                         id<CouchbaseValidationContext> context);
+
+/** Central per-process registry for native design-document functions.
+    Associates a key (a unique ID stored in the design doc as the "source" of the function)
+    with a C block.
+    This class is thread-safe. */
+@interface CouchbaseCallbacks : NSObject
+{
+    NSArray* _registries;
+}
+
++ (CouchbaseCallbacks*) sharedInstance;
+
+- (NSString*) generateKey;
+
+- (void) registerMapBlock: (CouchMapBlock)block forKey: (NSString*)key;
+- (void) registerReduceBlock: (CouchReduceBlock)block forKey: (NSString*)key;
+- (void) registerValidateUpdateBlock: (CouchValidateUpdateBlock)block forKey: (NSString*)key;
+
+- (CouchMapBlock) mapBlockForKey: (NSString*)key;
+- (CouchReduceBlock) reduceBlockForKey: (NSString*)key;
+- (CouchValidateUpdateBlock) validateUpdateBlockForKey: (NSString*)key;
+
+@end
+
+
+/** Context passed into a CouchValidateUpdateBlock. */
+@protocol CouchbaseValidationContext <NSObject>
+
+/** The contents of the current revision of the document, or nil if this is a new document. */
+@property (readonly) NSDictionary* currentRevision;
+
+/** The name of the database being updated. */
+@property (readonly) NSString* databaseName;
+
+/** The name of the logged-in user, or nil if this is an anonymous request. */
+@property (readonly) NSString* userName;
+
+/** Does the user have admin privileges?
+    (If the database is in the default "admin party" mode, this will be YES even when the userName is nil.) */
+@property (readonly) BOOL isAdmin;
+
+/** The database's security object, which assigns roles and privileges. */
+@property (readonly) NSDictionary* security;
+
+/** The type of error to report, if the validate block returns NO.
+    The default value is "forbidden", which will result in an HTTP 403 status. */
+@property (copy) NSString* errorType;
+
+/** The error message to return in the HTTP response, if the validate block returns NO.
+    The default value is "invalid document". */
+@property (copy) NSString* errorMessage;
+@end