Simplify project configuration by allowing only one backend per project

annif/project.py

@@ -36,7 +36,7 @@ def __init__(self, project_id, config, datadir):
         self.vocab_id = config.get('vocab', None)
         self._base_datadir = datadir
         self._datadir = os.path.join(datadir, 'projects', self.project_id)
-        self.backends = self._setup_backends(config)
+        self.backend = self._setup_backend(config)
 
     def _get_datadir(self):
         """return the path of the directory where this project can store its
@@ -45,16 +45,10 @@ def _get_datadir(self):
             os.makedirs(self._datadir)
         return self._datadir
 
-    def _setup_backends(self, config):
-        backends = []
-        for backend_id, weight in annif.util.parse_sources(config['backends']):
-            backend_type = annif.backend.get_backend(backend_id)
-            backend = backend_type(
-                backend_id,
-                params=config,
-                datadir=self._datadir)
-            backends.append((backend, weight))
-        return backends
+    def _setup_backend(self, config):
+        backend_id = config['backend']
+        backend_type = annif.backend.get_backend(backend_id)
+        return backend_type(backend_id, params=config, datadir=self._datadir)
 
     def _initialize_analyzer(self):
         analyzer = self.analyzer
@@ -80,40 +74,34 @@ def _initialize_vectorizer(self):
         except AnnifException as err:
             logger.warning(err.format_message())
 
-    def _initialize_backends(self):
-        logger.debug("Project '%s': initializing backends", self.project_id)
-        for backend, _ in self.backends:
-            try:
-                backend.initialize()
-            except AnnifException as err:
-                logger.warning(err.format_message())
+    def _initialize_backend(self):
+        logger.debug("Project '%s': initializing backend", self.project_id)
+        try:
+            self.backend.initialize()
+        except AnnifException as err:
+            logger.warning(err.format_message())
 
     def initialize(self):
-        """initialize this project and all backends so that they are ready to
+        """initialize this project and its backend so that they are ready to
         analyze"""
         logger.debug("Initializing project '%s'", self.project_id)
 
         self._initialize_analyzer()
         self._initialize_subjects()
         self._initialize_vectorizer()
-        self._initialize_backends()
+        self._initialize_backend()
 
         self.initialized = True
 
-    def _analyze_with_backends(self, text, backend_params):
-        hits_from_backends = []
+    def _analyze_with_backend(self, text, backend_params):
         if backend_params is None:
             backend_params = {}
-        for backend, weight in self.backends:
-            beparams = backend_params.get(backend.backend_id, {})
-            hits = backend.analyze(text, project=self, params=beparams)
-            logger.debug(
-                'Got %d hits from backend %s',
-                len(hits), backend.backend_id)
-            hits_from_backends.append(
-                annif.hit.WeightedHits(
-                    hits=hits, weight=weight))
-        return hits_from_backends
+        beparams = backend_params.get(self.backend.backend_id, {})
+        hits = self.backend.analyze(text, project=self, params=beparams)
+        logger.debug(
+            'Got %d hits from backend %s',
+            len(hits), self.backend.backend_id)
+        return hits
 
     @property
     def analyzer(self):
@@ -149,21 +137,18 @@ def vectorizer(self):
         return self._vectorizer
 
     def analyze(self, text, backend_params=None):
-        """Analyze the given text by passing it to backends and joining the
-        results. Returns a list of AnalysisHit objects ordered by decreasing
-        score."""
+        """Analyze the given text by passing it to the backend. Returns a
+        list of AnalysisHit objects ordered by decreasing score."""
 
         logger.debug('Analyzing text "%s..." (len=%d)',
                      text[:20], len(text))
-        hits_from_backends = self._analyze_with_backends(text, backend_params)
-        merged_hits = annif.util.merge_hits(hits_from_backends, self.subjects)
-        logger.debug('%d hits after merging', len(merged_hits))
-        return merged_hits
+        hits = self._analyze_with_backend(text, backend_params)
+        logger.debug('%d hits from backend', len(hits))
+        return hits
 
     def _create_vectorizer(self, subjectcorpus):
-        if True not in [
-                be[0].needs_subject_vectorizer for be in self.backends]:
-            logger.debug('not creating vectorizer: not needed by any backend')
+        if not self.backend.needs_subject_vectorizer:
+            logger.debug('not creating vectorizer: not needed by backend')
             return
         logger.info('creating vectorizer')
         self._vectorizer = TfidfVectorizer(
@@ -180,17 +165,14 @@ def load_documents(self, corpus):
 
         corpus.set_subject_index(self.subjects)
         self._create_vectorizer(corpus)
-
-        for backend, _ in self.backends:
-            backend.load_corpus(corpus, project=self)
+        self.backend.load_corpus(corpus, project=self)
 
     def dump(self):
         """return this project as a dict"""
         return {'project_id': self.project_id,
                 'name': self.name,
                 'language': self.language,
-                'backends': [{'backend_id': be[0].backend_id,
-                              'weight': be[1]} for be in self.backends]
+                'backend': {'backend_id': self.backend.backend_id}
                 }
 
 

annif/swagger/annif.yaml

@@ -97,12 +97,8 @@ definitions:
       backend_id:
         type: string
         example: my-backend
-      weight:
-        type: number
-        example: 1.0
     required:
       - backend_id
-      - weight
   Project:
     description: A project definition
     properties:
@@ -115,15 +111,13 @@ definitions:
       language:
         type: string
         example: en
-      backends:
-        type: array
-        items:
-          $ref: '#/definitions/ProjectBackend'
+      backend:
+        $ref: '#/definitions/ProjectBackend'
     required:
       - project_id
       - name
       - language
-      - backends
+      - backend
   ProjectList:
     description: A list of projects
     properties:

projects.cfg.dist

@@ -3,31 +3,31 @@
 [tfidf-fi]
 name=TF-IDF Finnish
 language=fi
-backends=tfidf
+backend=tfidf
 analyzer=voikko(fi)
 limit=100
 vocab=yso-fi
 
 [tfidf-sv]
 name=TF-IDF Swedish
 language=sv
-backends=tfidf
+backend=tfidf
 analyzer=snowball(swedish)
 limit=100
 vocab=yso-sv
 
 [tfidf-en]
 name=TF-IDF English
 language=en
-backends=tfidf
+backend=tfidf
 analyzer=snowball(english)
 limit=100
 vocab=yso-en
 
 [fasttext-fi]
 name=fastText Finnish
 language=fi
-backends=fasttext
+backend=fasttext
 analyzer=voikko(fi)
 dim=500
 lr=0.25
@@ -40,7 +40,7 @@ vocab=yso-fi
 [fasttext-sv]
 name=fastText Swedish
 language=sv
-backends=fasttext
+backend=fasttext
 analyzer=snowball(swedish)
 dim=500
 lr=0.25
@@ -53,7 +53,7 @@ vocab=yso-sv
 [fasttext-en]
 name=fastText English
 language=en
-backends=fasttext
+backend=fasttext
 analyzer=snowball(english)
 dim=500
 lr=0.25
@@ -66,44 +66,44 @@ vocab=yso-en
 [maui-fi]
 name=Maui Finnish
 language=fi
-backends=http
+backend=http
 endpoint=http://localhost:8080/maui/jyu-fin/analyze
 vocab=yso-fi
 
 [maui-sv]
 name=Maui Swedish
 language=sv
-backends=http
+backend=http
 endpoint=http://localhost:8080/maui/jyu-swe/analyze
 vocab=yso-sv
 
 [maui-en]
 name=Maui English
 language=en
-backends=http
+backend=http
 endpoint=http://localhost:8080/maui/jyu-eng/analyze
 vocab=yso-en
 
 [annif-api-fi]
 name=Annif prototype API Finnish
 language=fi
-backends=http
+backend=http
 endpoint=http://api.annif.org/v0/autoindex
 project=yso-finna-fi
 vocab=yso-fi
 
 [annif-api-sv]
 name=Annif prototype API Swedish
 language=sv
-backends=http
+backend=http
 endpoint=http://api.annif.org/v0/autoindex
 project=yso-finna-sv
 vocab=yso-sv
 
 [annif-api-en]
 name=Annif prototype API English
 language=en
-backends=http
+backend=http
 endpoint=http://api.annif.org/v0/autoindex
 project=yso-finna-en
 vocab=yso-en

tests/projects.cfg

@@ -3,71 +3,71 @@
 [dummy-fi]
 name=Dummy Finnish
 language=fi
-backends=dummy
+backend=dummy
 analyzer=snowball(finnish)
 key=value
 vocab=dummy
 
 [dummy-en]
 name=Dummy English
 language=en
-backends=dummy:0.5
+backend=dummy
 analyzer=snowball(english)
 vocab=dummy
 
 [dummydummy]
 name=Dummy+Dummy combination
 language=en
-backends=dummy:2,dummy
+backend=dummy
 analyzer=snowball(english)
 vocab=dummy
 
 [ensemble]
 name=Ensemble
 language=en
-backends=ensemble
+backend=ensemble
 sources=dummy-en,dummydummy
 vocab=dummy
 
 [noanalyzer]
 name=Dummy with no analyzer
 language=en
-backends=dummy
+backend=dummy
 vocab=dummy
 
 [novocab]
 name=TFIDF with no vocab
 language=en
-backends=tfidf
+backend=tfidf
 analyzer=snowball(english)
 
 [pav]
 name=PAV Ensemble Finnish
 language=fi
-backends=pav
+backend=pav
 sources=tfidf-fi,fasttext-fi
 vocab=yso-fi
 
 [tfidf-fi]
 name=TF-IDF Finnish
 language=fi
-backends=tfidf
+backend=tfidf
 analyzer=snowball(finnish)
 limit=10
 vocab=yso-fi
 
 [tfidf-en]
 name=TF-IDF English
 language=en
-backends=tfidf
+backend=tfidf
 analyzer=snowball(english)
 limit=10
 vocab=yso-en
 
 [fasttext-en]
 name=fastText English
 language=en
-backends=fasttext
+backend=fasttext
 analyzer=snowball(english)
 dim=100
 lr=0.25
@@ -80,7 +80,7 @@ vocab=yso-en
 [fasttext-fi]
 name=fastText Finnish
 language=fi
-backends=fasttext
+backend=fasttext
 analyzer=snowball(finnish)
 dim=100
 lr=0.25