Bucket object¶

class couchbase.bucket.Bucket¶

Passing Arguments¶

All keyword arguments passed to methods should be specified as keyword arguments, and the user should not rely on their position within the keyword specification - as this is subject to change.

Thus, if a function is prototyped as:

def foo(self, key, foo=None, bar=1, baz=False)

then arguments passed to foo() should always be in the form of

obj.foo(key, foo=fooval, bar=barval, baz=bazval)

and never like

obj.foo(key, fooval, barval, bazval)

Arguments To `*_multi` Methods¶

Arguments passed to *_multi methods involves passing an iterable of keys. The iterable must have __len__ and __iter__ implemented.

For operations which require values (i.e. the upsert_multi() family), a dict must be passed with the values set as the values which should be stored for the keys.

Some of the multi methods accept keyword arguments; these arguments apply to all the keys within the iterable passed.

You can also pass an ItemCollection as the keys or kv parameter. The Item interfaces allows in-place modifications to an object across multiple operations avoiding the need for copying the result into your own data structure.

See the documentation for Item for more information.

Key and Value Format¶

By default, keys are encoded as UTF-8, while values are encoded as JSON; which was selected to be the default for compatibility and ease-of-use with views.

Format Options¶

The following constants may be used as values to the format option in methods where this is supported. This is also the value returned in the flags attribute of the ValueResult object from a get() operation.

Each format specifier has specific rules about what data types it accepts.

couchbase.FMT_JSON¶: Indicates the value is to be converted to JSON. This accepts any plain Python object and internally calls json.dumps(value)(). See the Python json documentation for more information. It is recommended you use this format if you intend to examine the value in a MapReduce view function

couchbase.FMT_PICKLE¶: Convert the value to Pickle. This is the most flexible format as it accepts just about any Python object. This should not be used if operating in environments where other Couchbase clients in other languages might be operating (as Pickle is a Python-specific format)

couchbase.FMT_BYTES¶

Pass the value as a byte string. No conversion is performed, but the value must already be of a bytes type. In Python 2.x bytes is a synonym for str. In Python 3.x, bytes and str are distinct types. Use this option to store “binary” data. An exception will be thrown if a unicode object is passed, as unicode objects do not have any specific encoding. You must first encode the object to your preferred encoding and pass it along as the value.

Note that values with FMT_BYTES are retrieved as byte objects.

FMT_BYTES is the quickest conversion method.

couchbase.FMT_UTF8¶

Pass the value as a UTF-8 encoded string. This accepts unicode objects. It may also accept str objects if their content is encodable as UTF-8 (otherwise a ValueFormatError is thrown).

Values with FMT_UTF8 are retrieved as unicode objects (for Python 3 unicode objects are plain str objects).

couchbase.FMT_AUTO¶

Automatically determine the format of the input type. The value of this constant is an opaque object.

The rules are as follows:

If the value is a str, FMT_UTF8 is used. If it is a bytes object then FMT_BYTES is used. If it is a list, tuple or dict, bool, or None then FMT_JSON is used. For anything else FMT_PICKLE is used.

Key Format¶

The above format options are only valid for values being passed to one of the storage methods (see couchbase.bucket.Bucket.upsert()).

For keys, the acceptable inputs are those for FMT_UTF8

Single-Key Data Methods¶

These methods all return a Result object containing information about the operation (such as status and value).

Storing Data¶

class couchbase.bucket.Bucket: These methods set the contents of a key in Couchbase. If successful, they replace the existing contents (if any) of the key.

Retrieving Data¶

class couchbase.bucket.Bucket

Modifying Data¶

These methods modify existing values in Couchbase

class couchbase.bucket.Bucket

Entry Operations¶

These methods affect an entry in Couchbase. They do not directly modify the value, but may affect the entry’s accessibility or duration.

class couchbase.bucket.Bucket

Counter Operations¶

These are atomic counter operations for Couchbase. They increment or decrement a counter. A counter is a key whose value can be parsed as an integer. Counter values may be retrieved (without modification) using the Bucket.get() method

class couchbase.bucket.Bucket

Multi-Key Data Methods¶

These methods tend to be more efficient than their single-key equivalents. They return a couchbase.result.MultiResult object (which is a dict subclass) which contains class:couchbase.result.Result objects as the values for its keys

class couchbase.bucket.Bucket

Batch Operation Pipeline¶

In addition to the multi methods, you may also use the Pipeline context manager to schedule multiple operations of different types

class couchbase.bucket.Bucket

class couchbase.bucket.Pipeline¶

MapReduce/View Methods¶

class couchbase.bucket.Bucket

Design Document Management¶

To perform design document management operations, you must first get an instance of the BucketManager. You can do this by invoking the bucket_manager() method on the Bucket object.

Note

Design document management functions are async. This means that any successful return value simply means that the operation was scheduled successfuly on the server. It is possible that the view or design will still not yet exist after creating, deleting, or publishing a design document. Therefore it may be recommended to verify that the view exists by “polling” until the view does not fail. This may be accomplished by specifying the syncwait parameter to the various design methods which accept them.

Note

The normal process for dealing with views and design docs is to first create a development design document. Such design documents are prefixed with the string dev_. They operate on a small subset of cluster data and as such are ideal for testing as they do not impact load very much.

Once you are satisfied with the behavior of the development design doc, you can publish it into a production mode design doc. Such design documents always operate on the full cluster dataset.

The view and design functions accept a use_devmode parameter which prefixes the design name with dev_ if not already prefixed.

class couchbase.bucketmanager.BucketManager¶

class couchbase.bucket.Bucket

Informational Methods¶

These methods do not operate on keys directly, but offer various information about things

class couchbase.bucket.Bucket

Item API Methods¶

These methods are specifically for the Item API. Most of the multi methods will accept Item objects as well, however there are some special methods for this interface

class couchbase.bucket.Bucket

Durability Constraints¶

Durability constraints ensure safer protection against data loss.

class couchbase.bucket.Bucket

Attributes¶

class couchbase.bucket.Bucket

default_format¶

Specify the default format (default: FMT_JSON) to encode your data before storing in Couchbase. It uses the flags field to store the format.

See Key and Value Format for the possible values

On a get() the original value will be returned. This means the JSON will be decoded, respectively the object will be unpickled.

Private APIs¶

class couchbase.bucket.Bucket: The following APIs are not supported because using them is inherently dangerous. They are provided as workarounds for specific problems which may be encountered by users, and for potential testing of certain states and/or modifications which are not attainable with the public API.

Additional Connection Options¶

This section is intended to document some of the less common connection options and formats of the connection string (see couchbase.bucket.Bucket.__init__()).

Using Custom Ports¶

If you require to connect to an alternate port for bootstrapping the client (either because your administrator has configured the cluster to listen on alternate ports, or because you are using the built-in cluster_run script provided with the server source code), you may do so in the host list itself.

Simply provide the host in the format of host:port.

Note that the port is dependent on the scheme used. In this case, the scheme dictates what specific service the port points to.

Scheme	Protocol
`couchbase`	memcached port (default is `11210`)
`couchbases`	SSL-encrypted memcached port (default is `11207`)
`http`	REST API/Administrative port (default is `8091`)

Options in Connection String¶

Additional client options may be specified within the connection string itself. These options are derived from the underlying libcouchbase library and thus will accept any input accepted by the library itself. The following are some influential options:

config_total_timeout. Number of seconds to wait for the client bootstrap to complete.
config_node_timeout. Maximum number of time to wait (in seconds) to attempt to bootstrap from the current node. If the bootstrap times out (and the config_total_timeout setting is not reached), the bootstrap is then attempted from the next node (or an exception is raised if no more nodes remain).
config_cache. If set, this will refer to a file on the filesystem where cached “bootstrap” information may be stored. This path may be shared among multiple instance of the Couchbase client. Using this option may reduce overhead when using many short-lived instances of the client.

If the file does not exist, it will be created.