7 files changed, 1258 insertions, 0 deletions
diff --git a/prometheus_client/__init__.py b/prometheus_client/__init__.py
new file mode 100644
index 0000000..80424db
--- /dev/null
+++ b/prometheus_client/__init__.py
@@ -0,0 +1,49 @@
+#!/usr/bin/python
+
+from . import core
+from . import exposition
+from . import process_collector
+
+__all__ = ['Counter', 'Gauge', 'Summary', 'Histogram']
+# http://stackoverflow.com/questions/19913653/no-unicode-in-all-for-a-packages-init
+__all__ = [n.encode('ascii') for n in __all__]
+
+CollectorRegistry = core.CollectorRegistry
+REGISTRY = core.REGISTRY
+Metric = core.Metric
+Counter = core.Counter
+Gauge = core.Gauge
+Summary = core.Summary
+Histogram = core.Histogram
+
+CONTENT_TYPE_LATEST = exposition.CONTENT_TYPE_LATEST
+generate_latest = exposition.generate_latest
+MetricsHandler = exposition.MetricsHandler
+start_http_server = exposition.start_http_server
+write_to_textfile = exposition.write_to_textfile
+push_to_gateway = exposition.push_to_gateway
+pushadd_to_gateway = exposition.pushadd_to_gateway
+delete_from_gateway = exposition.delete_from_gateway
+instance_ip_grouping_key = exposition.instance_ip_grouping_key
+
+ProcessCollector = process_collector.ProcessCollector
+PROCESS_COLLECTOR = process_collector.PROCESS_COLLECTOR
+
+
+if __name__ == '__main__':
+    c = Counter('cc', 'A counter')
+    c.inc()
+
+    g = Gauge('gg', 'A gauge')
+    g.set(17)
+
+    s = Summary('ss', 'A summary', ['a', 'b'])
+    s.labels('c', 'd').observe(17)
+
+    h = Histogram('hh', 'A histogram')
+    h.observe(.6)
+
+    start_http_server(8000)
+    import time
+    while True:
+      time.sleep(1)
diff --git a/prometheus_client/bridge/__init__.py b/prometheus_client/bridge/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/prometheus_client/bridge/__init__.py
diff --git a/prometheus_client/bridge/graphite.py b/prometheus_client/bridge/graphite.py
new file mode 100644
index 0000000..a01c312
--- /dev/null
+++ b/prometheus_client/bridge/graphite.py
@@ -0,0 +1,80 @@
+#!/usr/bin/python
+from __future__ import unicode_literals
+
+import logging
+import re
+import socket
+import time
+import threading
+
+from .. import core
+
+# Roughly, have to keep to what works as a file name.
+# We also remove periods, so labels can be distinguished.
+_INVALID_GRAPHITE_CHARS = re.compile(r"[^a-zA-Z0-9_-]")
+
+
+def _sanitize(s):
+    return _INVALID_GRAPHITE_CHARS.sub('_', s)
+
+
+class _RegularPush(threading.Thread):
+    def __init__(self, pusher, interval, prefix):
+        super(_RegularPush, self).__init__()
+        self._pusher = pusher
+        self._interval = interval
+        self._prefix = prefix
+
+    def run(self):
+        wait_until = time.time()
+        while True:
+            while True:
+                now = time.time()
+                if now >= wait_until:
+                    # May need to skip some pushes.
+                    while wait_until < now:
+                        wait_until += self._interval
+                    break
+                # time.sleep can return early.
+                time.sleep(wait_until - now)
+            try:
+                self._pusher.push(prefix=self._prefix)
+            except IOError:
+                logging.exception("Push failed")
+
+
+class GraphiteBridge(object):
+    def __init__(self, address, registry=core.REGISTRY, timeout_seconds=30, _time=time):
+        self._address = address
+        self._registry = registry
+        self._timeout = timeout_seconds
+        self._time = _time
+
+    def push(self, prefix=''):
+        now = int(self._time.time())
+        output = []
+
+        prefixstr = ''
+        if prefix:
+            prefixstr = prefix + '.'
+
+        for metric in self._registry.collect():
+            for name, labels, value in metric.samples:
+                if labels:
+                    labelstr = '.' + '.'.join(
+                        ['{0}.{1}'.format(
+                             _sanitize(k), _sanitize(v))
+                             for k, v in sorted(labels.items())])
+                else:
+                    labelstr = ''
+                output.append('{0}{1}{2} {3} {4}\n'.format(
+                    prefixstr, _sanitize(name), labelstr, float(value), now))
+
+        conn = socket.create_connection(self._address, self._timeout)
+        conn.sendall(''.join(output).encode('ascii'))
+        conn.close()
+
+    def start(self, interval=60.0, prefix=''):
+        t = _RegularPush(self, interval, prefix)
+        t.daemon = True
+        t.start()
diff --git a/prometheus_client/core.py b/prometheus_client/core.py
new file mode 100644
index 0000000..14b5394
--- /dev/null
+++ b/prometheus_client/core.py
@@ -0,0 +1,679 @@
+#!/usr/bin/python
+
+from __future__ import unicode_literals
+
+import copy
+import math
+import re
+import time
+import types
+
+try:
+    from BaseHTTPServer import BaseHTTPRequestHandler
+except ImportError:
+    # Python 3
+    unicode = str
+
+from functools import wraps
+from threading import Lock
+
+_METRIC_NAME_RE = re.compile(r'^[a-zA-Z_:][a-zA-Z0-9_:]*$')
+_METRIC_LABEL_NAME_RE = re.compile(r'^[a-zA-Z_:][a-zA-Z0-9_:]*$')
+_RESERVED_METRIC_LABEL_NAME_RE = re.compile(r'^__.*$')
+_INF = float("inf")
+_MINUS_INF = float("-inf")
+
+
+class CollectorRegistry(object):
+    '''Metric collector registry.
+
+    Collectors must have a no-argument method 'collect' that returns a list of
+    Metric objects. The returned metrics should be consistent with the Prometheus
+    exposition formats.
+    '''
+    def __init__(self):
+        self._collectors = set()
+        self._lock = Lock()
+
+    def register(self, collector):
+        '''Add a collector to the registry.'''
+        with self._lock:
+            self._collectors.add(collector)
+
+    def unregister(self, collector):
+        '''Remove a collector from the registry.'''
+        with self._lock:
+            self._collectors.remove(collector)
+
+    def collect(self):
+        '''Yields metrics from the collectors in the registry.'''
+        collectors = None
+        with self._lock:
+            collectors = copy.copy(self._collectors)
+        for collector in collectors:
+            for metric in collector.collect():
+                yield metric
+
+    def get_sample_value(self, name, labels=None):
+        '''Returns the sample value, or None if not found.
+
+        This is inefficient, and intended only for use in unittests.
+        '''
+        if labels is None:
+            labels = {}
+        for metric in self.collect():
+            for n, l, value in metric.samples:
+                if n == name and l == labels:
+                    return value
+        return None
+
+
+REGISTRY = CollectorRegistry()
+'''The default registry.'''
+
+_METRIC_TYPES = ('counter', 'gauge', 'summary', 'histogram', 'untyped')
+
+
+class Metric(object):
+    '''A single metric family and its samples.
+
+    This is intended only for internal use by the instrumentation client.
+
+    Custom collectors should use GaugeMetricFamily, CounterMetricFamily
+    and SummaryMetricFamily instead.
+    '''
+    def __init__(self, name, documentation, typ):
+        self.name = name
+        self.documentation = documentation
+        if typ not in _METRIC_TYPES:
+            raise ValueError('Invalid metric type: ' + typ)
+        self.type = typ
+        self.samples = []
+
+    def add_sample(self, name, labels, value):
+        '''Add a sample to the metric.
+
+        Internal-only, do not use.'''
+        self.samples.append((name, labels, value))
+
+    def __eq__(self, other):
+        return (isinstance(other, Metric)
+                and self.name == other.name
+                and self.documentation == other.documentation
+                and self.type == other.type
+                and self.samples == other.samples)
+
+
+class CounterMetricFamily(Metric):
+    '''A single counter and its samples.
+
+    For use by custom collectors.
+    '''
+    def __init__(self, name, documentation, value=None, labels=None):
+        Metric.__init__(self, name, documentation, 'counter')
+        if labels is not None and value is not None:
+            raise ValueError('Can only specify at most one of value and labels.')
+        if labels is None:
+          labels = []
+        self._labelnames = labels
+        if value is not None:
+          self.add_metric([], value)
+
+    def add_metric(self, labels, value):
+        '''Add a metric to the metric family.
+
+        Args:
+          labels: A list of label values
+          value: The value of the metric.
+        '''
+        self.samples.append((self.name, dict(zip(self._labelnames, labels)), value))
+
+
+class GaugeMetricFamily(Metric):
+    '''A single gauge and its samples.
+
+    For use by custom collectors.
+    '''
+    def __init__(self, name, documentation, value=None, labels=None):
+        Metric.__init__(self, name, documentation, 'gauge')
+        if labels is not None and value is not None:
+            raise ValueError('Can only specify at most one of value and labels.')
+        if labels is None:
+          labels = []
+        self._labelnames = labels
+        if value is not None:
+          self.add_metric([], value)
+
+    def add_metric(self, labels, value):
+        '''Add a metric to the metric family.
+
+        Args:
+          labels: A list of label values
+          value: A float
+        '''
+        self.samples.append((self.name, dict(zip(self._labelnames, labels)), value))
+
+
+class SummaryMetricFamily(Metric):
+    '''A single summary and its samples.
+
+    For use by custom collectors.
+    '''
+    def __init__(self, name, documentation, count_value=None, sum_value=None, labels=None):
+        Metric.__init__(self, name, documentation, 'summary')
+        if (sum_value is None) != (count_value is None):
+            raise ValueError('count_value and sum_value must be provided together.')
+        if labels is not None and count_value is not None:
+            raise ValueError('Can only specify at most one of value and labels.')
+        if labels is None:
+          labels = []
+        self._labelnames = labels
+        if count_value is not None:
+          self.add_metric([], count_value, sum_value)
+
+    def add_metric(self, labels, count_value, sum_value):
+        '''Add a metric to the metric family.
+
+        Args:
+          labels: A list of label values
+          count_value: The count value of the metric.
+          sum_value: The sum value of the metric.
+        '''
+        self.samples.append((self.name + '_count', dict(zip(self._labelnames, labels)), count_value))
+        self.samples.append((self.name + '_sum', dict(zip(self._labelnames, labels)), sum_value))
+
+
+class HistogramMetricFamily(Metric):
+    '''A single histogram and its samples.
+
+    For use by custom collectors.
+    '''
+    def __init__(self, name, documentation, buckets=None, sum_value=None, labels=None):
+        Metric.__init__(self, name, documentation, 'histogram')
+        if (sum_value is None) != (buckets is None):
+            raise ValueError('buckets and sum_value must be provided together.')
+        if labels is not None and buckets is not None:
+            raise ValueError('Can only specify at most one of buckets and labels.')
+        if labels is None:
+          labels = []
+        self._labelnames = labels
+        if buckets is not None:
+          self.add_metric([], buckets, sum_value)
+
+    def add_metric(self, labels, buckets, sum_value):
+        '''Add a metric to the metric family.
+
+        Args:
+          labels: A list of label values
+          buckets: A list of pairs of bucket names and values.
+              The buckets must be sorted, and +Inf present.
+          sum_value: The sum value of the metric.
+        '''
+        for bucket, value in buckets:
+          self.samples.append((self.name + '_bucket', dict(list(zip(self._labelnames, labels)) + [('le', bucket)]), value))
+        # +Inf is last and provides the count value.
+        self.samples.append((self.name + '_count', dict(zip(self._labelnames, labels)), buckets[-1][1]))
+        self.samples.append((self.name + '_sum', dict(zip(self._labelnames, labels)), sum_value))
+
+
+class _MutexValue(object):
+    '''A float protected by a mutex.'''
+
+    def __init__(self, name, labelnames, labelvalues):
+      self._value = 0.0
+      self._lock = Lock()
+
+    def inc(self, amount):
+      with self._lock:
+          self._value += amount
+
+    def set(self, value):
+      with self._lock:
+          self._value = value
+
+    def get(self):
+      with self._lock:
+          return self._value
+
+_ValueClass = _MutexValue
+
+
+class _LabelWrapper(object):
+    '''Handles labels for the wrapped metric.'''
+    def __init__(self, wrappedClass, name, labelnames, **kwargs):
+        self._wrappedClass = wrappedClass
+        self._type = wrappedClass._type
+        self._name = name
+        self._labelnames = labelnames
+        self._kwargs = kwargs
+        self._lock = Lock()
+        self._metrics = {}
+
+        for l in labelnames:
+            if l.startswith('__'):
+                raise ValueError('Invalid label metric name: ' + l)
+
+    def labels(self, *labelvalues):
+        '''Return the child for the given labelset.
+
+        Labels can be provided as a tuple or as a dict:
+            c = Counter('c', 'counter', ['l', 'm'])
+            # Set labels by position
+            c.labels('0', '1').inc()
+            # Set labels by name
+            c.labels({'l': '0', 'm': '1'}).inc()
+        '''
+        if len(labelvalues) == 1 and type(labelvalues[0]) == dict:
+            if sorted(labelvalues[0].keys()) != sorted(self._labelnames):
+                raise ValueError('Incorrect label names')
+            labelvalues = tuple([unicode(labelvalues[0][l]) for l in self._labelnames])
+        else:
+            if len(labelvalues) != len(self._labelnames):
+                raise ValueError('Incorrect label count')
+            labelvalues = tuple([unicode(l) for l in labelvalues])
+        with self._lock:
+            if labelvalues not in self._metrics:
+                self._metrics[labelvalues] = self._wrappedClass(self._name, self._labelnames, labelvalues, **self._kwargs)
+            return self._metrics[labelvalues]
+
+    def remove(self, *labelvalues):
+        '''Remove the given labelset from the metric.'''
+        if len(labelvalues) != len(self._labelnames):
+            raise ValueError('Incorrect label count')
+        labelvalues = tuple([unicode(l) for l in labelvalues])
+        with self._lock:
+            del self._metrics[labelvalues]
+
+    def _samples(self):
+        with self._lock:
+            metrics = self._metrics.copy()
+        for labels, metric in metrics.items():
+            series_labels = list(dict(zip(self._labelnames, labels)).items())
+            for suffix, sample_labels, value in metric._samples():
+                yield (suffix, dict(series_labels + list(sample_labels.items())), value)
+
+
+def _MetricWrapper(cls):
+    '''Provides common functionality for metrics.'''
+    def init(name, documentation, labelnames=(), namespace='', subsystem='', registry=REGISTRY, **kwargs):
+        full_name = ''
+        if namespace:
+            full_name += namespace + '_'
+        if subsystem:
+            full_name += subsystem + '_'
+        full_name += name
+
+        if labelnames:
+            labelnames = tuple(labelnames)
+            for l in labelnames:
+                if not _METRIC_LABEL_NAME_RE.match(l):
+                    raise ValueError('Invalid label metric name: ' + l)
+                if _RESERVED_METRIC_LABEL_NAME_RE.match(l):
+                    raise ValueError('Reserved label metric name: ' + l)
+                if l in cls._reserved_labelnames:
+                    raise ValueError('Reserved label metric name: ' + l)
+            collector = _LabelWrapper(cls, name, labelnames, **kwargs)
+        else:
+            collector = cls(name, labelnames, (), **kwargs)
+
+        if not _METRIC_NAME_RE.match(full_name):
+            raise ValueError('Invalid metric name: ' + full_name)
+
+        def collect():
+            metric = Metric(full_name, documentation, cls._type)
+            for suffix, labels, value in collector._samples():
+                metric.add_sample(full_name + suffix, labels, value)
+            return [metric]
+        collector.collect = collect
+
+        if registry:
+            registry.register(collector)
+        return collector
+
+    return init
+
+
+@_MetricWrapper
+class Counter(object):
+    '''A Counter tracks counts of events or running totals.
+
+    Example use cases for Counters:
+    - Number of requests processed
+    - Number of items that were inserted into a queue
+    - Total amount of data that a system has processed
+
+    Counters can only go up (and be reset when the process restarts). If your use case can go down,
+    you should use a Gauge instead.
+
+    An example for a Counter:
+
+    from prometheus_client import Counter
+    c = Counter('my_failures_total', 'Description of counter')
+    c.inc()     # Increment by 1
+    c.inc(1.6)  # Increment by given value
+    '''
+    _type = 'counter'
+    _reserved_labelnames = []
+
+    def __init__(self, name, labelnames, labelvalues):
+        self._value = _ValueClass(name, labelnames, labelvalues)
+
+    def inc(self, amount=1):
+        '''Increment counter by the given amount.'''
+        if amount < 0:
+            raise ValueError('Counters can only be incremented by non-negative amounts.')
+        self._value.inc(amount)
+
+    def count_exceptions(self, exception=Exception):
+        '''Count exceptions in a block of code or function.
+
+        Can be used as a function decorator or context manager.
+        Increments the counter when an exception of the given
+        type is raised up out of the code.
+        '''
+
+        class ExceptionCounter(object):
+            def __init__(self, counter):
+                self._counter = counter
+
+            def __enter__(self):
+                pass
+
+            def __exit__(self, typ, value, traceback):
+                if isinstance(value, exception):
+                    self._counter.inc()
+
+            def __call__(self, f):
+                @wraps(f)
+                def wrapped(*args, **kwargs):
+                    with self:
+                        return f(*args, **kwargs)
+                return wrapped
+
+        return ExceptionCounter(self)
+
+    def _samples(self):
+        return (('', {}, self._value.get()), )
+
+
+@_MetricWrapper
+class Gauge(object):
+    '''Gauge metric, to report instantaneous values.
+
+     Examples of Gauges include:
+        Inprogress requests
+        Number of items in a queue
+        Free memory
+        Total memory
+        Temperature
+
+     Gauges can go both up and down.
+
+        from prometheus_client import Gauge
+        g = Gauge('my_inprogress_requests', 'Description of gauge')
+        g.inc()      # Increment by 1
+        g.dec(10)    # Decrement by given value
+        g.set(4.2)   # Set to a given value
+    '''
+    _type = 'gauge'
+    _reserved_labelnames = []
+
+    def __init__(self, name, labelnames, labelvalues):
+        self._value = _ValueClass(name, labelnames, labelvalues)
+
+    def inc(self, amount=1):
+        '''Increment gauge by the given amount.'''
+        self._value.inc(amount)
+
+    def dec(self, amount=1):
+        '''Decrement gauge by the given amount.'''
+        self._value.inc(-amount)
+
+    def set(self, value):
+        '''Set gauge to the given value.'''
+        self._value.set(float(value))
+
+    def set_to_current_time(self):
+        '''Set gauge to the current unixtime.'''
+        self.set(time.time())
+
+    def track_inprogress(self):
+        '''Track inprogress blocks of code or functions.
+
+        Can be used as a function decorator or context manager.
+        Increments the gauge when the code is entered,
+        and decrements when it is exited.
+        '''
+
+        class InprogressTracker(object):
+            def __init__(self, gauge):
+                self._gauge = gauge
+
+            def __enter__(self):
+                self._gauge.inc()
+
+            def __exit__(self, typ, value, traceback):
+                self._gauge.dec()
+
+            def __call__(self, f):
+                @wraps(f)
+                def wrapped(*args, **kwargs):
+                    with self:
+                        return f(*args, **kwargs)
+                return wrapped
+
+        return InprogressTracker(self)
+
+    def time(self):
+        '''Time a block of code or function, and set the duration in seconds.
+
+        Can be used as a function decorator or context manager.
+        '''
+
+        class Timer(object):
+            def __init__(self, gauge):
+                self._gauge = gauge
+
+            def __enter__(self):
+                self._start = time.time()
+
+            def __exit__(self, typ, value, traceback):
+                # Time can go backwards.
+                self._gauge.set(max(time.time() - self._start, 0))
+
+            def __call__(self, f):
+                @wraps(f)
+                def wrapped(*args, **kwargs):
+                    with self:
+                        return f(*args, **kwargs)
+                return wrapped
+
+        return Timer(self)
+
+    def set_function(self, f):
+        '''Call the provided function to return the Gauge value.
+
+        The function must return a float, and may be called from
+        multiple threads.
+        All other methods of the Gauge become NOOPs.
+        '''
+        def samples(self):
+            return (('', {}, float(f())), )
+        self._samples = types.MethodType(samples, self)
+
+    def _samples(self):
+        return (('', {}, self._value.get()), )
+
+
+@_MetricWrapper
+class Summary(object):
+    '''A Summary tracks the size and number of events.
+
+    Example use cases for Summaries:
+    - Response latency
+    - Request size
+
+    Example for a Summary:
+
+    from prometheus_client import Summary
+    s = Summary('request_size_bytes', 'Request size (bytes)')
+    s.observe(512)  # Observe 512 (bytes)
+
+    Example for a Summary using time:
+    from prometheus_client import Summary
+    REQUEST_TIME = Summary('response_latency_seconds', 'Response latency (seconds)')
+
+    @REQUEST_TIME.time()
+    def create_response(request):
+      """A dummy function"""
+      time.sleep(1)
+
+    '''
+    _type = 'summary'
+    _reserved_labelnames = ['quantile']
+
+    def __init__(self, name, labelnames, labelvalues):
+        self._count = _ValueClass(name + '_count', labelnames, labelvalues)
+        self._sum = _ValueClass(name + '_sum', labelnames, labelvalues)
+
+    def observe(self, amount):
+        '''Observe the given amount.'''
+        self._count.inc(1)
+        self._sum.inc(amount)
+
+    def time(self):
+        '''Time a block of code or function, and observe the duration in seconds.
+
+        Can be used as a function decorator or context manager.
+        '''
+
+        class Timer(object):
+            def __init__(self, summary):
+                self._summary = summary
+
+            def __enter__(self):
+                self._start = time.time()
+
+            def __exit__(self, typ, value, traceback):
+                # Time can go backwards.
+                self._summary.observe(max(time.time() - self._start, 0))
+
+            def __call__(self, f):
+                @wraps(f)
+                def wrapped(*args, **kwargs):
+                    with self:
+                        return f(*args, **kwargs)
+                return wrapped
+
+        return Timer(self)
+
+    def _samples(self):
+        return (
+            ('_count', {}, self._count.get()),
+            ('_sum', {}, self._sum.get()))
+
+
+def _floatToGoString(d):
+    if d == _INF:
+        return '+Inf'
+    elif d == _MINUS_INF:
+        return '-Inf'
+    elif math.isnan(d):
+        return 'NaN'
+    else:
+        return repr(float(d))
+
+
+@_MetricWrapper
+class Histogram(object):
+    '''A Histogram tracks the size and number of events in buckets.
+
+    You can use Histograms for aggregatable calculation of quantiles.
+
+    Example use cases:
+    - Response latency
+    - Request size
+
+    Example for a Histogram:
+
+    from prometheus_client import Histogram
+    h = Histogram('request_size_bytes', 'Request size (bytes)')
+    h.observe(512)  # Observe 512 (bytes)
+
+
+    Example for a Histogram using time:
+    from prometheus_client import Histogram
+    REQUEST_TIME = Histogram('response_latency_seconds', 'Response latency (seconds)')
+
+    @REQUEST_TIME.time()
+    def create_response(request):
+      """A dummy function"""
+      time.sleep(1)
+
+    The default buckets are intended to cover a typical web/rpc request from milliseconds to seconds.
+    They can be overridden by passing `buckets` keyword argument to `Histogram`.
+    '''
+    _type = 'histogram'
+    _reserved_labelnames = ['histogram']
+
+    def __init__(self, name, labelnames, labelvalues, buckets=(.005, .01, .025, .05, .075, .1, .25, .5, .75, 1.0, 2.5, 5.0, 7.5, 10.0, _INF)):
+        self._sum = _ValueClass(name + '_sum', labelnames, labelvalues)
+        buckets = [float(b) for b in buckets]
+        if buckets != sorted(buckets):
+            # This is probably an error on the part of the user,
+            # so raise rather than sorting for them.
+            raise ValueError('Buckets not in sorted order')
+        if buckets and buckets[-1] != _INF:
+            buckets.append(_INF)
+        if len(buckets) < 2:
+            raise ValueError('Must have at least two buckets')
+        self._upper_bounds = buckets
+        self._buckets = []
+        bucket_labelnames = labelnames + ('le',)
+        for b in buckets:
+          self._buckets.append(_ValueClass(name + '_bucket', bucket_labelnames, labelvalues + (_floatToGoString(b),)))
+
+    def observe(self, amount):
+        '''Observe the given amount.'''
+        self._sum.inc(amount)
+        for i, bound in enumerate(self._upper_bounds):
+            if amount <= bound:
+                self._buckets[i].inc(1)
+                break
+
+    def time(self):
+        '''Time a block of code or function, and observe the duration in seconds.
+
+        Can be used as a function decorator or context manager.
+        '''
+
+        class Timer(object):
+            def __init__(self, histogram):
+                self._histogram = histogram
+
+            def __enter__(self):
+                self._start = time.time()
+
+            def __exit__(self, typ, value, traceback):
+                # Time can go backwards.
+                self._histogram.observe(max(time.time() - self._start, 0))
+
+            def __call__(self, f):
+                @wraps(f)
+                def wrapped(*args, **kwargs):
+                    with self:
+                        return f(*args, **kwargs)
+                return wrapped
+
+        return Timer(self)
+
+    def _samples(self):
+        samples = []
+        acc = 0
+        for i, bound in enumerate(self._upper_bounds):
+            acc += self._buckets[i].get()
+            samples.append(('_bucket', {'le': _floatToGoString(bound)}, acc))
+        samples.append(('_count', {}, acc))
+        samples.append(('_sum', {}, self._sum.get()))
+        return tuple(samples)
+
diff --git a/prometheus_client/exposition.py b/prometheus_client/exposition.py
new file mode 100644
index 0000000..3c4795d
--- /dev/null
+++ b/prometheus_client/exposition.py
@@ -0,0 +1,131 @@
+#!/usr/bin/python
+
+from __future__ import unicode_literals
+
+import os
+import socket
+import time
+import threading
+from contextlib import closing
+
+from . import core
+try:
+    from BaseHTTPServer import BaseHTTPRequestHandler
+    from BaseHTTPServer import HTTPServer
+    from urllib2 import build_opener, Request, HTTPHandler
+    from urllib import quote_plus
+except ImportError:
+    # Python 3
+    unicode = str
+    from http.server import BaseHTTPRequestHandler
+    from http.server import HTTPServer
+    from urllib.request import build_opener, Request, HTTPHandler
+    from urllib.parse import quote_plus
+
+
+CONTENT_TYPE_LATEST = 'text/plain; version=0.0.4; charset=utf-8'
+'''Content type of the latest text format'''
+
+
+def generate_latest(registry=core.REGISTRY):
+    '''Returns the metrics from the registry in latest text format as a string.'''
+    output = []
+    for metric in registry.collect():
+        output.append('# HELP {0} {1}'.format(
+            metric.name, metric.documentation.replace('\\', r'\\').replace('\n', r'\n')))
+        output.append('\n# TYPE {0} {1}\n'.format(metric.name, metric.type))
+        for name, labels, value in metric.samples:
+            if labels:
+                labelstr = '{{{0}}}'.format(','.join(
+                    ['{0}="{1}"'.format(
+                     k, v.replace('\\', r'\\').replace('\n', r'\n').replace('"', r'\"'))
+                     for k, v in sorted(labels.items())]))
+            else:
+                labelstr = ''
+            output.append('{0}{1} {2}\n'.format(name, labelstr, core._floatToGoString(value)))
+    return ''.join(output).encode('utf-8')
+
+
+class MetricsHandler(BaseHTTPRequestHandler):
+    def do_GET(self):
+        self.send_response(200)
+        self.send_header('Content-Type', CONTENT_TYPE_LATEST)
+        self.end_headers()
+        self.wfile.write(generate_latest(core.REGISTRY))
+
+    def log_message(self, format, *args):
+        return
+
+
+def start_http_server(port, addr=''):
+    """Starts a HTTP server for prometheus metrics as a daemon thread."""
+    class PrometheusMetricsServer(threading.Thread):
+        def run(self):
+            httpd = HTTPServer((addr, port), MetricsHandler)
+            httpd.serve_forever()
+    t = PrometheusMetricsServer()
+    t.daemon = True
+    t.start()
+
+
+def write_to_textfile(path, registry):
+    '''Write metrics to the given path.
+
+    This is intended for use with the Node exporter textfile collector.
+    The path must end in .prom for the textfile collector to process it.'''
+    tmppath = '%s.%s.%s' % (path, os.getpid(), threading.current_thread().ident)
+    with open(tmppath, 'wb') as f:
+        f.write(generate_latest(registry))
+    # rename(2) is atomic.
+    os.rename(tmppath, path)
+
+
+def push_to_gateway(gateway, job, registry, grouping_key=None, timeout=None):
+    '''Push metrics to the given pushgateway.
+
+    This overwrites all metrics with the same job and grouping_key.
+    This uses the PUT HTTP method.'''
+    _use_gateway('PUT', gateway, job, registry, grouping_key, timeout)
+
+
+def pushadd_to_gateway(gateway, job, registry, grouping_key=None, timeout=None):
+    '''PushAdd metrics to the given pushgateway.
+
+    This replaces metrics with the same name, job and grouping_key.
+    This uses the POST HTTP method.'''
+    _use_gateway('POST', gateway, job, registry, grouping_key, timeout)
+
+
+def delete_from_gateway(gateway, job, grouping_key=None, timeout=None):
+    '''Delete metrics from the given pushgateway.
+
+    This deletes metrics with the given job and grouping_key.
+    This uses the DELETE HTTP method.'''
+    _use_gateway('DELETE', gateway, job, None, grouping_key, timeout)
+
+
+def _use_gateway(method, gateway, job, registry, grouping_key, timeout):
+    url = 'http://{0}/metrics/job/{1}'.format(gateway, quote_plus(job))
+
+    data = b''
+    if method != 'DELETE':
+        data = generate_latest(registry)
+
+    if grouping_key is None:
+        grouping_key = {}
+    url = url + ''.join(['/{0}/{1}'.format(quote_plus(str(k)), quote_plus(str(v)))
+                             for k, v in sorted(grouping_key.items())])
+
+    request = Request(url, data=data)
+    request.add_header('Content-Type', CONTENT_TYPE_LATEST)
+    request.get_method = lambda: method
+    resp = build_opener(HTTPHandler).open(request, timeout=timeout)
+    if resp.code >= 400:
+        raise IOError("error talking to pushgateway: {0} {1}".format(
+            resp.code, resp.msg))
+
+def instance_ip_grouping_key():
+    '''Grouping key with instance set to the IP Address of this host.'''
+    with closing(socket.socket(socket.AF_INET, socket.SOCK_DGRAM)) as s:
+        s.connect(('localhost', 0))
+        return {'instance': s.getsockname()[0]}
diff --git a/prometheus_client/parser.py b/prometheus_client/parser.py
new file mode 100644
index 0000000..4ca3d7c
--- /dev/null
+++ b/prometheus_client/parser.py
@@ -0,0 +1,224 @@
+#!/usr/bin/python
+
+from __future__ import unicode_literals
+
+try:
+    import StringIO
+except ImportError:
+    # Python 3
+    import io as StringIO
+
+from . import core
+
+
+def text_string_to_metric_families(text):
+    """Parse Prometheus text format from a string.
+
+    See text_fd_to_metric_families.
+    """
+    for metric_family in text_fd_to_metric_families(StringIO.StringIO(text)):
+      yield metric_family
+
+
+def _unescape_help(text):
+    result = []
+    slash = False
+
+    for char in text:
+        if slash:
+            if char == '\\':
+                result.append('\\')
+            elif char == 'n':
+                result.append('\n')
+            else:
+                result.append('\\' + char)
+            slash = False
+        else:
+          if char == '\\':
+              slash = True
+          else:
+              result.append(char)
+
+    if slash:
+        result.append('\\')
+
+    return ''.join(result)
+
+
+def _parse_sample(text):
+    name = []
+    labelname = []
+    labelvalue = []
+    value = []
+    labels = {}
+
+    state = 'name'
+
+    for char in text:
+        if state == 'name':
+            if char == '{':
+                state = 'startoflabelname'
+            elif char == ' ' or char == '\t':
+                state = 'endofname'
+            else:
+                name.append(char)
+        elif state == 'endofname':
+            if char == ' ' or char == '\t':
+                pass
+            elif char == '{':
+                state = 'startoflabelname'
+            else:
+                value.append(char)
+                state = 'value'
+        elif state == 'startoflabelname':
+            if char == ' ' or char == '\t':
+                pass
+            elif char == '}':
+                state = 'endoflabels'
+            else:
+                state = 'labelname'
+                labelname.append(char)
+        elif state == 'labelname':
+            if char == '=':
+                state = 'labelvaluequote'
+            elif char == ' ' or char == '\t':
+                state = 'labelvalueequals'
+            else:
+                labelname.append(char)
+        elif state == 'labelvalueequals':
+            if char == '=':
+                state = 'labelvaluequote'
+            elif char == ' ' or char == '\t':
+                pass
+            else:
+                raise ValueError("Invalid line: " + text)
+        elif state == 'labelvaluequote':
+            if char == '"':
+                state = 'labelvalue'
+            elif char == ' ' or char == '\t':
+                pass
+            else:
+                raise ValueError("Invalid line: " + text)
+        elif state == 'labelvalue':
+            if char == '\\':
+                state = 'labelvalueslash'
+            elif char == '"':
+                labels[''.join(labelname)] = ''.join(labelvalue)
+                labelname = []
+                labelvalue = []
+                state = 'nextlabel'
+            else:
+                labelvalue.append(char)
+        elif state == 'labelvalueslash':
+            state = 'labelvalue'
+            if char == '\\':
+                labelvalue.append('\\')
+            elif char == 'n':
+                labelvalue.append('\n')
+            elif char == '"':
+                labelvalue.append('"')
+            else:
+                labelvalue.append('\\' + char)
+        elif state == 'nextlabel':
+            if char == ',':
+                state = 'labelname'
+            elif char == '}':
+                state = 'endoflabels'
+            elif char == ' ' or char == '\t':
+                pass
+            else:
+                raise ValueError("Invalid line: " + text)
+        elif state == 'endoflabels':
+            if char == ' ' or char == '\t':
+                pass
+            else:
+                value.append(char)
+                state = 'value'
+        elif state == 'value':
+            if char == ' ' or char == '\t':
+                # Timestamps are not supported, halt
+                break
+            else:
+                value.append(char)
+    return (''.join(name), labels, float(''.join(value)))
+    
+
+def text_fd_to_metric_families(fd):
+    """Parse Prometheus text format from a file descriptor.
+
+    This is a laxer parser than the main Go parser,
+    so successful parsing does not imply that the parsed
+    text meets the specification.
+
+    Yields core.Metric's.
+    """
+    name = ''
+    documentation = ''
+    typ = 'untyped'
+    samples = []
+    allowed_names = []
+
+    def build_metric(name, documentation, typ, samples):
+        metric = core.Metric(name, documentation, typ)
+        metric.samples = samples
+        return metric
+
+    for line in fd:
+        line = line.strip()
+
+        if line.startswith('#'):
+            parts = line.split(None, 3)
+            if len(parts) < 2:
+                continue
+            if parts[1] == 'HELP':
+                if parts[2] != name:
+                    if name != '':
+                        yield build_metric(name, documentation, typ, samples)
+                    # New metric
+                    name = parts[2]
+                    typ = 'untyped'
+                    samples = []
+                    allowed_names = [parts[2]]
+                if len(parts) == 4:
+                  documentation = _unescape_help(parts[3])
+                else:
+                  documentation = ''
+            elif parts[1] == 'TYPE':
+                if parts[2] != name:
+                    if name != '':
+                        yield build_metric(name, documentation, typ, samples)
+                    # New metric
+                    name = parts[2]
+                    documentation = ''
+                    samples = []
+                typ = parts[3]
+                allowed_names = {
+                    'counter': [''],
+                    'gauge': [''],
+                    'summary': ['_count', '_sum', ''],
+                    'histogram': ['_count', '_sum', '_bucket'],
+                    }.get(typ, [parts[2]])
+                allowed_names = [name + n for n in allowed_names]
+            else:
+                # Ignore other comment tokens
+                pass
+        elif line == '':
+            # Ignore blank lines
+            pass
+        else:
+            sample = _parse_sample(line)
+            if sample[0] not in allowed_names:
+                  if name != '':
+                      yield build_metric(name, documentation, typ, samples)
+                  # New metric, yield immediately as untyped singleton
+                  name = ''
+                  documentation = ''
+                  typ = 'untyped'
+                  samples = []
+                  allowed_names = []
+                  yield build_metric(sample[0], documentation, typ, [sample])
+            else:
+              samples.append(sample)
+
+    if name != '':
+        yield build_metric(name, documentation, typ, samples)
diff --git a/prometheus_client/process_collector.py b/prometheus_client/process_collector.py
new file mode 100644
index 0000000..5c906c9
--- /dev/null
+++ b/prometheus_client/process_collector.py
@@ -0,0 +1,95 @@
+#!/usr/bin/python
+
+from __future__ import unicode_literals
+
+import os
+import time
+import threading
+
+from . import core
+try:
+  import resource
+  _PAGESIZE = resource.getpagesize()
+except ImportError:
+  # Not Unix
+  _PAGESIZE = 4096
+
+
+class ProcessCollector(object):
+    """Collector for Standard Exports such as cpu and memory."""
+    def __init__(self, namespace='', pid=lambda: 'self', proc='/proc', registry=core.REGISTRY):
+        self._namespace = namespace
+        self._pid = pid
+        self._proc = proc
+        if namespace:
+            self._prefix = namespace + '_process_'
+        else:
+            self._prefix = 'process_'
+        self._ticks = 100.0
+        try:
+            self._ticks = os.sysconf('SC_CLK_TCK')
+        except (ValueError, TypeError, AttributeError):
+            pass
+
+        # This is used to test if we can access /proc.
+        self._btime = 0
+        try:
+            self._btime = self._boot_time()
+        except IOError:
+            pass
+        if registry:
+          registry.register(self)
+
+    def _boot_time(self):
+        with open(os.path.join(self._proc, 'stat')) as stat:
+            for line in stat:
+                if line.startswith('btime '):
+                    return float(line.split()[1])
+
+    def collect(self):
+        if not self._btime:
+            return []
+
+        try:
+          pid = os.path.join(self._proc, str(self._pid()).strip())
+        except:
+          # File likely didn't exist, fail silently.
+          raise
+          return []
+
+        result = []
+        try:
+            with open(os.path.join(pid, 'stat')) as stat:
+                parts = (stat.read().split(')')[-1].split())
+            vmem = core.GaugeMetricFamily(self._prefix + 'virtual_memory_bytes',
+                    'Virtual memory size in bytes', value=float(parts[20]))
+            rss = core.GaugeMetricFamily(self._prefix + 'resident_memory_bytes', 'Resident memory size in bytes', value=float(parts[21]) * _PAGESIZE)
+            start_time_secs = float(parts[19]) / self._ticks
+            start_time = core.GaugeMetricFamily(self._prefix + 'start_time_seconds',
+                    'Start time of the process since unix epoch in seconds.', value=start_time_secs + self._btime)
+            utime = float(parts[11]) / self._ticks
+            stime = float(parts[12]) / self._ticks
+            cpu = core.CounterMetricFamily(self._prefix + 'cpu_seconds_total',
+                    'Total user and system CPU time spent in seconds.', value=utime + stime)
+            result.extend([vmem, rss, start_time, cpu])
+        except IOError:
+            pass
+
+        try:
+            with open(os.path.join(pid, 'limits')) as limits:
+                for line in limits:
+                    if line.startswith('Max open file'):
+                        max_fds = core.GaugeMetricFamily(self._prefix + 'max_fds',
+                                'Maximum number of open file descriptors.', value=float(line.split()[3]))
+                        break
+            open_fds = core.GaugeMetricFamily(self._prefix + 'open_fds',
+                    'Number of open file descriptors.', len(os.listdir(os.path.join(pid, 'fd'))))
+            result.extend([open_fds, max_fds])
+        except IOError:
+            pass
+
+        return result
+
+
+PROCESS_COLLECTOR = ProcessCollector()
+"""Default ProcessCollector in default Registry REGISTRY."""