Small improvements made to the compressdev programmer's guide.
This includes rephrasing some sentences, fixing grammar,
and aligning formatting.
Fixes: a584d3bea902 ("doc: add compressdev library guide")
Fixes: f7095d41bba6 ("doc: clarify data plane error handling in compressdev")
Cc: ashish.gu...@caviumnetworks.com
Cc: fiona.tr...@intel.com
Cc: sta...@dpdk.org
Signed-off-by: Ciara Power <ciara.po...@intel.com>
---
doc/guides/prog_guide/compressdev.rst | 283 ++++++++++++++------------
1 file changed, 148 insertions(+), 135 deletions(-)
diff --git a/doc/guides/prog_guide/compressdev.rst
b/doc/guides/prog_guide/compressdev.rst
index 07d1a62a63..2a59c434c1 100644
--- a/doc/guides/prog_guide/compressdev.rst
+++ b/doc/guides/prog_guide/compressdev.rst
@@ -2,7 +2,7 @@
Copyright(c) 2017-2018 Cavium Networks.
Compression Device Library
-===========================
+==========================
The compression framework provides a generic set of APIs to perform
compression services
as well as to query and configure compression devices both physical(hardware)
and virtual(software)
@@ -32,10 +32,10 @@ From the command line using the --vdev EAL option
.. Note::
- * If DPDK application requires multiple software compression PMD devices
then required
- number of ``--vdev`` with appropriate libraries are to be added.
+ * If a DPDK application requires multiple software compression PMD devices
then the
+ required number of ``--vdev`` args with appropriate libraries are to be
added.
- * An Application with multiple compression device instances exposed by the
same PMD must
+ * An application with multiple compression device instances exposed by the
same PMD must
specify a unique name for each device.
Example: ``--vdev 'pmd0' --vdev 'pmd1'``
@@ -53,7 +53,7 @@ All virtual compression devices support the following
initialization parameters:
Device Identification
~~~~~~~~~~~~~~~~~~~~~
-Each device, whether virtual or physical is uniquely designated by two
+Each device, whether virtual or physical, is uniquely designated by two
identifiers:
- A unique device index used to designate the compression device in all
functions
@@ -76,7 +76,7 @@ The ``rte_compressdev_configure`` API is used to configure a
compression device.
The ``rte_compressdev_config`` structure is used to pass the configuration
parameters.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
Configuration of Queue Pairs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -85,87 +85,88 @@ Each compression device queue pair is individually
configured through the
``rte_compressdev_queue_pair_setup`` API.
The ``max_inflight_ops`` is used to pass maximum number of
-rte_comp_op that could be present in a queue at-a-time.
-PMD then can allocate resources accordingly on a specified socket.
+``rte_comp_op`` that could be present in a queue at a time.
+The PMD can then allocate resources accordingly on a specified socket.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
-Logical Cores, Memory and Queues Pair Relationships
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Logical Cores, Memory and Queue Pair Relationships
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Library supports NUMA similarly as described in Cryptodev library section.
+The Compressdev library supports NUMA similarly as described in Cryptodev
library section.
-A queue pair cannot be shared and should be exclusively used by a single
processing
-context for enqueuing operations or dequeuing operations on the same
compression device
+A queue pair cannot be shared, and should be exclusively used by a single
processing
+context for enqueuing operations or dequeuing operations on the same
compression device,
since sharing would require global locks and hinder performance. It is however
possible
to use a different logical core to dequeue an operation on a queue pair from
the logical
-core on which it was enqueued. This means that a compression burst
enqueue/dequeue
+core on which it was enqueued. This means that for a compression burst,
enqueue/dequeue
APIs are a logical place to transition from one logical core to another in a
data processing pipeline.
Device Features and Capabilities
----------------------------------
+--------------------------------
Compression devices define their functionality through two mechanisms, global
device
-features and algorithm features. Global devices features identify device
-wide level features which are applicable to the whole device such as supported
hardware
+features and algorithm features. Global device features identify device
+wide level features which are applicable to the whole device, such as
supported hardware
acceleration and CPU features. List of compression device features can be seen
in the
RTE_COMPDEV_FF_XXX macros.
-The algorithm features lists individual algo feature which device supports
per-algorithm,
-such as a stateful compression/decompression, checksums operation etc. List of
algorithm
-features can be seen in the RTE_COMP_FF_XXX macros.
+The algorithm features are features which the device supports per-algorithm,
+such as a stateful compression/decompression, checksums operation etc.
+The list of algorithm features can be seen in the RTE_COMP_FF_XXX macros.
Capabilities
~~~~~~~~~~~~
Each PMD has a list of capabilities, including algorithms listed in
-enum ``rte_comp_algorithm`` and its associated feature flag and
-sliding window range in log base 2 value. Sliding window tells
-the minimum and maximum size of lookup window that algorithm uses
+the enum ``rte_comp_algorithm``, its associated feature flag, and
+sliding window range in log base 2 value. The sliding window range
+defines the minimum and maximum size of a lookup window that an algorithm uses
to find duplicates.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
Each Compression poll mode driver defines its array of capabilities
-for each algorithm it supports. See PMD implementation for capability
+for each algorithm it supports. See the PMD implementation for capability
initialization.
Capabilities Discovery
~~~~~~~~~~~~~~~~~~~~~~
-PMD capability and features are discovered via ``rte_compressdev_info_get``
function.
+PMD capability and features are discovered via the
``rte_compressdev_info_get`` function.
The ``rte_compressdev_info`` structure contains all the relevant information
for the device.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
Compression Operation
-----------------------
+---------------------
DPDK compression supports two types of compression methodologies:
-- Stateless, data associated to a compression operation is compressed without
any reference
+- Stateless - data associated with a compression operation is compressed
without any reference
to another compression operation.
-- Stateful, data in each compression operation is compressed with reference to
previous compression
+- Stateful - data in each compression operation is compressed with reference
to previous compression
operations in the same data stream i.e. history of data is maintained
between the operations.
-For more explanation, please refer RFC https://www.ietf.org/rfc/rfc1951.txt
+For more explanation, please refer to the RFC
https://www.ietf.org/rfc/rfc1951.txt
Operation Representation
~~~~~~~~~~~~~~~~~~~~~~~~
-Compression operation is described via ``struct rte_comp_op``, which contains
both input and
+A compression operation is described via ``struct rte_comp_op``, which
contains both input and
output data. The operation structure includes the operation type (stateless or
stateful),
-the operation status and the priv_xform/stream handle, source, destination and
checksum buffer
+the operation status, the priv_xform/stream handle, source, destination and
checksum buffer
pointers. It also contains the source mempool from which the operation is
allocated.
-PMD updates consumed field with amount of data read from source buffer and
produced
-field with amount of data of written into destination buffer along with status
of
-operation. See section *Produced, Consumed And Operation Status* for more
details.
-
-Compression operations mempool also has an ability to allocate private memory
with the
-operation for application's purposes. Application software is responsible for
specifying
-all the operation specific fields in the ``rte_comp_op`` structure which are
then used
+The PMD updates the consumed field with the amount of data read from the
source buffer,
+and the produced field with the amount of data written into the destination
buffer,
+along with status of operation.
+See the section :ref:`compressdev_prod_cons_op_status`: for more details.
+
+The compression operations mempool also has the ability to allocate private
memory with the
+operation for the application's use. The application software is responsible
for specifying
+all the operation specific fields in the ``rte_comp_op`` structure, which are
then used
by the compression PMD to process the requested operation.
@@ -181,27 +182,27 @@ A ``rte_comp_op`` contains a field indicating the pool it
originated from.
``rte_comp_op_alloc()`` and ``rte_comp_op_bulk_alloc()`` are used to allocate
compression operations from a given compression operation mempool.
-The operation gets reset before being returned to a user so that operation
+The operation gets reset before being returned to a user so that the operation
is always in a good known state before use by the application.
``rte_comp_op_free()`` is called by the application to return an operation to
its allocating pool.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
Passing source data as mbuf-chain
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If input data is scattered across several different buffers, then
-Application can either parse through all such buffers and make one
+the application can either parse through all such buffers and make one
mbuf-chain and enqueue it for processing or, alternatively, it can
-make multiple sequential enqueue_burst() calls for each of them
-processing them statefully. See *Compression API Stateful Operation*
+make multiple sequential enqueue_burst() calls for each of them,
+processing them statefully. See :ref:`compressdev_stateful_op`:
for stateful processing of ops.
Operation Status
~~~~~~~~~~~~~~~~
-Each operation carries a status information updated by PMD after it is
processed.
-Following are currently supported:
+Each operation carries status information updated by the PMD after it is
processed.
+The following are currently supported:
- RTE_COMP_OP_STATUS_SUCCESS,
Operation is successfully completed
@@ -225,22 +226,25 @@ Following are currently supported:
- RTE_COMP_OP_STATUS_OUT_OF_SPACE_RECOVERABLE,
Output buffer ran out of space before operation completed, but this
is not an error case. Output data up to op.produced can be used and
- next op in the stream should continue on from op.consumed+1.
+ the next op in the stream should continue on from op.consumed+1.
Operation status after enqueue / dequeue
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Some of the above values may arise in the op after an
-``rte_compressdev_enqueue_burst()``. If number ops enqueued < number ops
requested then
-the app should check the op.status of nb_enqd+1. If status is
RTE_COMP_OP_STATUS_NOT_PROCESSED,
-it likely indicates a full-queue case for a hardware device and a retry after
dequeuing some ops is likely
-to be successful. If the op holds any other status, e.g.
RTE_COMP_OP_STATUS_INVALID_ARGS, a retry with
+``rte_compressdev_enqueue_burst()``. If the number of ops enqueued < the
number of ops requested
+then the app should check the op.status of nb_enqd+1.
+If the status is RTE_COMP_OP_STATUS_NOT_PROCESSED, it likely indicates a
full-queue case for a
+hardware device, and a retry after dequeuing some ops is likely to be
successful.
+If the op holds any other status, e.g. RTE_COMP_OP_STATUS_INVALID_ARGS, a
retry with
the same op is unlikely to be successful.
+.. _compressdev_prod_cons_op_status:
+
Produced, Consumed And Operation Status
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- If status is RTE_COMP_OP_STATUS_SUCCESS,
+- If the status is RTE_COMP_OP_STATUS_SUCCESS,
consumed = amount of data read from input buffer, and
produced = amount of data written in destination buffer
- If status is RTE_COMP_OP_STATUS_ERROR,
@@ -253,37 +257,37 @@ Produced, Consumed And Operation Status
- If status is RTE_COMP_OP_STATUS_OUT_OF_SPACE_RECOVERABLE,
consumed = amount of data read, and
produced = amount of data successfully produced until
- out of space condition hit. PMD has ability to recover
- from here, so application can submit next op from
- consumed+1 and a destination buffer with available space.
+ out of space condition hit. The PMD has ability to recover
+ from here, so an application can submit the next op from
+ consumed+1, and a destination buffer with available space.
Transforms
----------
Compression transforms (``rte_comp_xform``) are the mechanism
to specify the details of the compression operation such as algorithm,
-window size and checksum.
+window size, and checksum.
Compression API Hash support
----------------------------
-Compression API allows application to enable digest calculation
+The compression API allows an application to enable digest calculation
alongside compression and decompression of data. A PMD reflects its
support for hash algorithms via capability algo feature flags.
-If supported, PMD calculates digest always on plaintext i.e.
+If supported, the PMD always calculates the digest on plaintext i.e.
before compression and after decompression.
Currently supported list of hash algos are SHA-1 and SHA2 family
SHA256.
-See *DPDK API Reference* for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
-If required, application should set valid hash algo in compress
+If required, the application should set the valid hash algo in compress
or decompress xforms during ``rte_compressdev_stream_create()``
-or ``rte_compressdev_private_xform_create()`` and pass a valid
+or ``rte_compressdev_private_xform_create()``, and pass a valid
output buffer in ``rte_comp_op`` hash field struct to store the
-resulting digest. Buffer passed should be contiguous and large
-enough to store digest which is 20 bytes for SHA-1 and
+resulting digest. The buffer passed should be contiguous and large
+enough to store digest, which is 20 bytes for SHA-1 and
32 bytes for SHA2-256.
Compression API Stateless operation
@@ -295,20 +299,21 @@ An op is processed stateless if it has
(required only on compression side),
- All required input in source buffer
-When all of the above conditions are met, PMD initiates stateless processing
+When all of the above conditions are met, the PMD initiates stateless
processing
and releases acquired resources after processing of current operation is
-complete. Application can enqueue multiple stateless ops in a single burst
+complete. The application can enqueue multiple stateless ops in a single burst
and must attach priv_xform handle to such ops.
priv_xform in Stateless operation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-priv_xform is PMD internally managed private data that it maintains to do
stateless processing.
-priv_xforms are initialized provided a generic xform structure by an
application via making call
-to ``rte_compressdev_private_xform_create``, at an output PMD returns an
opaque priv_xform reference.
-If PMD support SHAREABLE priv_xform indicated via algorithm feature flag, then
application can
-attach same priv_xform with many stateless ops at-a-time. If not, then
application needs to
-create as many priv_xforms as it expects to have stateless operations
in-flight.
+A priv_xform is private data managed internally by the PMD to do stateless
processing.
+A priv_xform is initialized by an application providing a generic xform
structure
+to ``rte_compressdev_private_xform_create``, which returns an opaque
priv_xform reference.
+If the PMD supports SHAREABLE priv_xform, indicated via algorithm feature flag,
+then the application can attach the same priv_xform with many stateless ops at
a time.
+If not, then the application needs to create as many priv_xforms as it expects
to have
+stateless operations in-flight.
.. figure:: img/stateless-op.*
@@ -320,8 +325,9 @@ create as many priv_xforms as it expects to have stateless
operations in-flight.
Stateless Ops using Shareable priv_xform
-Application should call ``rte_compressdev_private_xform_create()`` and attach
to stateless op before
-enqueuing them for processing and free via
``rte_compressdev_private_xform_free()`` during termination.
+The application should call ``rte_compressdev_private_xform_create()`` and
attach it to a stateless
+op before enqueuing them for processing and free via
``rte_compressdev_private_xform_free()``
+during termination.
An example pseudocode to setup and process NUM_OPS stateless ops with each of
length OP_LEN
using priv_xform would look like:
@@ -399,75 +405,80 @@ using priv_xform would look like:
Stateless and OUT_OF_SPACE
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~
-OUT_OF_SPACE is a condition when output buffer runs out of space and where PMD
-still has more data to produce. If PMD runs into such condition, then PMD
returns
-RTE_COMP_OP_OUT_OF_SPACE_TERMINATED error. In such case, PMD resets itself and
can set
+OUT_OF_SPACE is a condition when the output buffer runs out of space and where
the PMD
+still has more data to produce. If the PMD runs into such condition, then the
PMD returns
+RTE_COMP_OP_OUT_OF_SPACE_TERMINATED error. In such case, the PMD resets itself
and can set
consumed=0 and produced=amount of output it could produce before hitting
out_of_space.
-Application would need to resubmit the whole input with a larger output
buffer, if it
+The application would need to resubmit the whole input with a larger output
buffer, if it
wants the operation to be completed.
Hash in Stateless
~~~~~~~~~~~~~~~~~
-If hash is enabled, digest buffer will contain valid data after op is
successfully
+If hash is enabled, the digest buffer will contain valid data after an op is
successfully
processed i.e. dequeued with status = RTE_COMP_OP_STATUS_SUCCESS.
Checksum in Stateless
~~~~~~~~~~~~~~~~~~~~~
-If checksum is enabled, checksum will only be available after op is
successfully
+If checksum is enabled, checksum will only be available after an op is
successfully
processed i.e. dequeued with status = RTE_COMP_OP_STATUS_SUCCESS.
+.. _compressdev_stateful_op:
+
Compression API Stateful operation
-----------------------------------
-Compression API provide RTE_COMP_FF_STATEFUL_COMPRESSION and
-RTE_COMP_FF_STATEFUL_DECOMPRESSION feature flag for PMD to reflect
+The compression API provides RTE_COMP_FF_STATEFUL_COMPRESSION and
+RTE_COMP_FF_STATEFUL_DECOMPRESSION feature flag for the PMD to reflect
its support for Stateful operations.
-A Stateful operation in DPDK compression means application invokes enqueue
-burst() multiple times to process related chunk of data because
-application broke data into several ops.
+A Stateful operation in DPDK compression means the application invokes enqueue
+burst() multiple times to process a related chunk of data because the
+application broke the data into several ops.
-In such case
+In such cases
- ops are setup with op_type RTE_COMP_OP_STATEFUL,
-- all ops except last set to flush value = RTE_COMP_FLUSH_NONE/SYNC
-and last set to flush value RTE_COMP_FLUSH_FULL/FINAL.
+- all ops except the last are set with flush value = RTE_COMP_FLUSH_NONE/SYNC
+and the last is set with flush value RTE_COMP_FLUSH_FULL/FINAL.
-In case of either one or all of the above conditions, PMD initiates
-stateful processing and releases acquired resources after processing
+In case of either one or all of the above conditions, the PMD initiates
+stateful processing and releases acquired resources after processing the
operation with flush value = RTE_COMP_FLUSH_FULL/FINAL is complete.
-Unlike stateless, application can enqueue only one stateful op from
-a particular stream at a time and must attach stream handle
+Unlike stateless, the application can enqueue only one stateful op from
+a particular stream at a time and must attach a stream handle
to each op.
Stream in Stateful operation
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-`stream` in DPDK compression is a logical entity which identifies related set
of ops, say, a one large
-file broken into multiple chunks then file is represented by a stream and each
chunk of that file is
-represented by compression op `rte_comp_op`. Whenever application wants a
stateful processing of such
-data, then it must get a stream handle via making call to
``rte_compressdev_stream_create()``
-with xform, at an output the target PMD will return an opaque stream handle to
application which
-it must attach to all of the ops carrying data of that stream. In stateful
processing, every op
-requires previous op data for compression/decompression. A PMD allocates and
set up resources such
-as history, states, etc. within a stream, which are maintained during the
processing of the related ops.
+A stream in DPDK compression is a logical entity which identifies a related
set of ops.
+For example, one large file broken into multiple chunks, then the file is
represented by a stream,
+and each chunk of that file is represented by a compression op ``rte_comp_op``.
+Whenever an application wants stateful processing of such data, then it must
get a stream handle
+via making call to ``rte_compressdev_stream_create()`` with an xform, which
will return an opaque
+stream handle to attach to all of the ops carrying data of that stream.
+In stateful processing, every op requires previous op data for
compression/decompression.
+A PMD allocates and sets up resources such as history, states, etc. within a
stream,
+which are maintained during the processing of related ops.
-Unlike priv_xforms, stream is always a NON_SHAREABLE entity. One stream handle
must be attached to only
-one set of related ops and cannot be reused until all of them are processed
with status Success or failure.
+Unlike priv_xforms, a stream is always a NON_SHAREABLE entity. One stream
handle must be attached
+to only one set of related ops and cannot be reused until all of them are
processed with a
+success/failure status.
.. figure:: img/stateful-op.*
Stateful Ops
-Application should call ``rte_compressdev_stream_create()`` and attach to op
before
+An application should call ``rte_compressdev_stream_create()`` and attach it
to the op before
enqueuing them for processing and free via ``rte_compressdev_stream_free()``
during
-termination. All ops that are to be processed statefully should carry *same*
stream.
+termination. All ops that are to be processed statefully should carry the
*same* stream.
-See *DPDK API Reference* document for details.
+See the `DPDK API Reference
<https://doc.dpdk.org/api/rte__compressdev_8h.html>`_ for details.
-An example pseudocode to set up and process a stream having NUM_CHUNKS with
each chunk size of CHUNK_LEN would look like:
+An example pseudocode to set up and process a stream having NUM_CHUNKS,
+with each chunk size of CHUNK_LEN, would look like:
.. code-block:: c
@@ -549,64 +560,65 @@ An example pseudocode to set up and process a stream
having NUM_CHUNKS with each
Stateful and OUT_OF_SPACE
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~
-If PMD supports stateful operation, then OUT_OF_SPACE status is not an actual
-error for the PMD. In such case, PMD returns with status
+If a PMD supports stateful operation, then an OUT_OF_SPACE status is not an
actual
+error for the PMD. In such a case, the PMD returns with status
RTE_COMP_OP_STATUS_OUT_OF_SPACE_RECOVERABLE with consumed = number of input
bytes
-read and produced = length of complete output buffer.
-Application should enqueue next op with source starting at consumed+1 and an
+read, and produced = length of complete output buffer.
+The application should enqueue the next op with source starting at consumed+1,
and an
output buffer with available space.
Hash in Stateful
~~~~~~~~~~~~~~~~
-If enabled, digest buffer will contain valid digest after last op in stream
+If enabled, the digest buffer will contain valid digest after the last op in a
stream
(having flush = RTE_COMP_FLUSH_FINAL) is successfully processed i.e. dequeued
with status = RTE_COMP_OP_STATUS_SUCCESS.
Checksum in Stateful
~~~~~~~~~~~~~~~~~~~~
-If enabled, checksum will only be available after last op in stream
+If enabled, the checksum will only be available after the last op in a stream
(having flush = RTE_COMP_FLUSH_FINAL) is successfully processed i.e. dequeued
with status = RTE_COMP_OP_STATUS_SUCCESS.
Burst in compression API
--------------------------
+------------------------
Scheduling of compression operations on DPDK's application data path is
performed using a burst oriented asynchronous API set. A queue pair on a
compression
-device accepts a burst of compression operations using enqueue burst API. On
physical
-devices the enqueue burst API will place the operations to be processed
+device accepts a burst of compression operations using the enqueue burst API.
+On physical devices the enqueue burst API will place the operations to be
processed
on the device's hardware input queue, for virtual devices the processing of the
operations is usually completed during the enqueue call to the compression
device. The dequeue burst API will retrieve any processed operations available
from the queue pair on the compression device, from physical devices this is
usually
-directly from the devices processed queue, and for virtual device's from a
+directly from the devices processed queue, and for virtual device's from an
``rte_ring`` where processed operations are placed after being processed on the
enqueue call.
-A burst in DPDK compression can be a combination of stateless and stateful
operations with a condition
-that for stateful ops only one op at-a-time should be enqueued from a
particular stream i.e. no-two ops
-should belong to same stream in a single burst. However a burst may contain
multiple stateful ops as long
-as each op is attached to a different stream i.e. a burst can look like:
+A burst in DPDK compression can be a combination of stateless and stateful
operations with a
+condition that for stateful ops only one op at a time should be enqueued from
a particular stream
+i.e. two ops should never belong to the same stream in a single burst.
+However, a burst may contain multiple stateful ops, as long as each op is
attached to a different
+stream, i.e. a burst can look like:
+---------------+--------------+--------------+-----------------+--------------+--------------+
| enqueue_burst | op1.no_flush | op2.no_flush | op3.flush_final | op4.no_flush
| op5.no_flush |
+---------------+--------------+--------------+-----------------+--------------+--------------+
-Where, op1 .. op5 all belong to different independent data units. op1, op2,
op4, op5 must be stateful
-as stateless ops can only use flush full or final and op3 can be of type
stateless or stateful.
-Every op with type set to RTE_COMP_OP_STATELESS must be attached to priv_xform
and
-Every op with type set to RTE_COMP_OP_STATEFUL *must* be attached to stream.
+Where, op1 .. op5 all belong to different independent data units. op1, op2,
op4, op5 must be
+stateful as stateless ops can only use flush full or final and op3 can be of
type stateless or
+stateful. Every op with type set to RTE_COMP_OP_STATELESS must be attached to
priv_xform and
+every op with type set to RTE_COMP_OP_STATEFUL *must* be attached to stream.
Since each operation in a burst is independent and thus can be completed
-out-of-order, applications which need ordering, should setup per-op user data
-area with reordering information so that it can determine enqueue order at
+out of order, applications which need ordering should setup a per-op user data
+area, with reordering information so that it can determine enqueue order at
dequeue.
-Also if multiple threads calls enqueue_burst() on same queue pair then it’s
-application onus to use proper locking mechanism to ensure exclusive enqueuing
-of operations.
+Also, if multiple threads calls enqueue_burst() on the same queue pair then
it's
+the application's responsibility to use a proper locking mechanism to ensure
+exclusive enqueuing of operations.
Enqueue / Dequeue Burst APIs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -629,9 +641,10 @@ Sample code
-----------
There are unit test applications that show how to use the compressdev library
inside
-app/test/test_compressdev.c
+``app/test/test_compressdev.c``
Compression Device API
~~~~~~~~~~~~~~~~~~~~~~
-The compressdev Library API is described in the *DPDK API Reference* document.
+The compressdev Library API is described in the
+`DPDK API Reference <https://doc.dpdk.org/api/rte__compressdev_8h.html>`_.
--
2.25.1
