[doc] add blobs api doc

3 files changed, 56 insertions, 74 deletions

diff --git a/docs/reference/blobs/client.rst b/docs/reference/blobs/client.rst
index 75c3d997..734866fe 100644
--- a/docs/reference/blobs/client.rst
+++ b/docs/reference/blobs/client.rst
@@ -1,20 +1,47 @@
 Client-side blobs
 =================
 
-On the client-side, blobs can be managed using the BlobManager API.  The
-BlobManager is responsible for managing storage of blobs both in local and
-remote storages
+Data storage
+------------
+
+On the client-side, blobs can be managed using the ``BlobManager`` API, which
+is responsible for managing storage of blobs both in local and remote storages.
+See :ref:`blobmanager-api` and :ref:`blobs-sync-api` for information on the
+client-side API.
 
 All data is stored locally in the ``blobs`` table of a SQLCipher database
 called ``{uuid}_blobs.db`` that lies in the same directory as the Soledad
-Client's JSON documents database. Both databases are encrypted with the same
-symmetric secret. All actions performed locally are mirrored remotelly using
-the :ref:`http-blobs-api`.
-
-The BlobManager supports *namespaces* and *flags* and can list local and remote
-blobs, possibly filtering by flags and ordering by date (increasingly or
-decreasingly). It has helper methods to send or fetch all missing blobs, thus
-aiding in synchronization of local and remote data.
+Client's JSON documents database (see :ref:`client-databases`). All actions
+performed locally are mirrored remotelly using the :ref:`blobs-http-api`.
+
+Namespaces
+----------
+
+The Blobs API supports **namespaces** so that applications can store and fetch
+blobs without interfering in each another. Namespaces are also used to
+implement the server-side :ref:`incoming-http-api`, used for mail delivery. All
+methods that deal with blobs storage, transfer and flagging provide
+a `namespace` parameter. If no namespace is given, the value `default` is used.
+
+Remote flags
+------------
+
+In order to allow clients to control the processing of blobs that are delivered
+by external applications, the Blobs API has the concept of **remote flags**.
+The client can get and set the following flags for Blobs that reside in the
+server: ``PENDING``, ``PROCESSING``, ``PROCESSED``, and ``FAILED``.
+
+Remote listing
+--------------
+
+The client can obtain a list of blobs in the server side so it can compare with
+its own local list and queue up blobs for download and upload. The remote
+listing can be ordered by *upload date* and filtered by *namespace* and *flag*.
+The listing can also only return the number of matches instead of the whole
+content.
+
+Client-side encryption
+----------------------
 
 When uploading, the content of the blob is encrypted with a symmetric secret
 prior to being sent to the server. When downloading, the content of the blob is
diff --git a/docs/reference/blobs/server.rst b/docs/reference/blobs/server.rst
index 532fccd7..cda0b95c 100644
--- a/docs/reference/blobs/server.rst
+++ b/docs/reference/blobs/server.rst
@@ -1,68 +1,23 @@
 Server-side blobs
 =================
 
+The server-side implementation of blobs provides HTTP APIs for data storage
+using a filesystem backend.
+
+HTTP APIs
+---------
+
 Soledad Server provides two different REST APIs for interacting with blobs:
 
-* A public **HTTP Blobs API**, providing the *Blobs* service for Soledad Client
-  (i.e. actual users of the infrastructure).
+* A *public* :ref:`blobs-http-api`, providing the *Blobs* service for Soledad
+  Client (i.e. actual users of the infrastructure).
 
-* A local **HTTP Incoming Box API**, providing the delivery part of the
+* A *local* :ref:`incoming-http-api`, providing the delivery part of the
   :ref:`incoming-box` service, currently used for the MX mail delivery.
 
 Authentication is handled differently for each of the endpoints, see
 :ref:`authentication` for more details.
 
-
-.. _http-blobs-api:
-
-HTTP Blobs API
---------------
-
-The *public endpoint* provides the following REST API for interacting with the
-*Blobs* service:
-
-=========================== ========== ================================= ============================================
-path                        method     action                            accepted query string fields
-=========================== ========== ================================= ============================================
-``/blobs/{uuid}``           ``GET``    Get a list of blobs. filtered by  ``namespace``, ``filter_flag``, ``order_by``
-                                       a flag.
-``/blobs/{uuid}/{blob_id}`` ``GET``    Get the contents of a blob.       ``namespace``
-``/blobs/{uuid}/{blob_id}`` ``PUT``    Create a blob. The content of the ``namespace``
-                                       blob should be sent in the body
-                                       of the request.
-``/blobs/{uuid}/{blob_id}`` ``POST``   Set the flags for a blob. A list  ``namespace``
-                                       of flags should be sent in the
-                                       body of the request.
-``/blobs/{uuid}/{blob_id}`` ``DELETE`` Delete a blob.                    ``namespace``
-=========================== ========== ================================= ============================================
-
-The Blobs service supports *namespaces*. All requests can be modified by the
-``namespace`` query string parameter, and the results will be restricted to
-a certain namespace. When no namespace explicitelly given, the ``default``
-namespace is used.
-
-When listing blobs, the results can be filtered by flag and/or ordered by date
-using the ``filter_flag`` and ``order_by`` query string parameters. The
-possible values for ``order_by`` are ``date`` or ``+date`` for increasing
-order, or ``-date`` for decreasing order.
-
-
-HTTP Incoming Box API
----------------------
-
-The *local endpoint* provides the following REST API for interacting with the
-:ref:`incoming-box` service.
-
-============================== ========== =================================
-path                           method     action
-============================== ========== =================================
-``/incoming/{uuid}/{blob_id}`` ``PUT``    Create an incoming blob. The content of the blob should be sent in the body of the request.
-============================== ========== =================================
-
-All blobs created using this API are inserted under the namespace ``MX`` and
-flagged as ``PENDING``.
-
-
 .. _filesystem-backend:
 
 Filesystem backend
diff --git a/docs/reference/blobs/sync.rst b/docs/reference/blobs/sync.rst
index 729bb0ab..bdfad0cf 100644
--- a/docs/reference/blobs/sync.rst
+++ b/docs/reference/blobs/sync.rst
@@ -19,10 +19,10 @@ Synchronization status
 In the client-side, each has an associated synchronization status, which can be
 one of:
 
-- `SYNCED`: The blob exists both in this client and in the server.
-- `PENDING_UPLOAD`: The blob was inserted locally, but has not yet been uploaded.
-- `PENDING_DOWNLOAD`: The blob exists in the server, but has not yet been downloaded.
-- `FAILED_DOWNLOAD`: A download attempt has been made but the content is corrupted for some reason.
+- ``SYNCED``: The blob exists both in this client and in the server.
+- ``PENDING_UPLOAD``: The blob was inserted locally, but has not yet been uploaded.
+- ``PENDING_DOWNLOAD``: The blob exists in the server, but has not yet been downloaded.
+- ``FAILED_DOWNLOAD``: A download attempt has been made but the content is corrupted for some reason.
 
 Concurrency limits
 ------------------
@@ -41,8 +41,8 @@ the transfer has been successful or until there has been an unrecoverable
 transfer error. Currently, the only unrecoverable transfer error is a failed
 verification of the blob tag (i.e. a failed MAC verification).
 
-Successive transfer attempts have an increasing delay between them, to minimize
-competition for resources used by other concurrent transfer attempts. The delay
-starts with 10 seconds and increases to 20, 30, 40, 50, and finally 60 seconds
-on each new failed attempt. The delay for a new retry then stays at 60 seconds
-for new attempts.
+Successive failed transfer attempts of the same blob are separated by an
+increasing time interval to minimize competition for resources used by other
+concurrent transfer attempts. The interaval starts at 10 seconds and increases
+to 20, 30, 40, 50, and finally 60 seconds. All further retries will be
+separated by a 60 seconds time interval.