ValueSerializer: Support efficiently reading and writing one-byte strings.

ValueSerializer: Support efficiently reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in M58.

BUG=chromium:686159
Review-Url: https://codereview.chromium.org/2658793004
Cr-Commit-Position: refs/heads/master@{#42753}
Committed: https://chromium.googlesource.com/v8/v8/+/bf511b426ee5d65976e1b87c7bac134585f0fc9f

[jbroman, 2017-01-26 16:38:10]

The CQ bit was checked by jbroman@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-26 16:38:14]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jbroman, 2017-01-26 16:45:32]

The CQ bit was checked by jbroman@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-26 16:45:34]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jbroman, 2017-01-26 16:47:21]

Description was changed from

==========
ValueSerializer: Support reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

BUG=148757
==========

to

==========
ValueSerializer: Support reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=148757
==========

[commit-bot: I haz the power, 2017-01-26 17:26:33]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-26 17:26:34]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel_ng/buil...)
  v8_presubmit on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/33468)

[jbroman, 2017-01-27 18:33:10]

The CQ bit was checked by jbroman@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-27 18:33:12]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jbroman, 2017-01-27 18:48:17]

Description was changed from

==========
ValueSerializer: Support reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=148757
==========

to

==========
ValueSerializer: Support reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=chromium:686159
==========

[jbroman, 2017-01-27 18:53:24]

Description was changed from

==========
ValueSerializer: Support reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=chromium:686159
==========

to

==========
ValueSerializer: Support efficiently reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=chromium:686159
==========

[commit-bot: I haz the power, 2017-01-27 19:05:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-27 19:05:46]

Dry run: This issue passed the CQ dry run.

[jbroman, 2017-01-27 19:07:00]

jbroman@chromium.org changed reviewers:
+ jkummerow@chromium.org

[jbroman, 2017-01-27 19:07:01]

This eliminates a conversion from i::String to v8::String to get the UTF-8 data,
and is more efficient. WDYT?

(I'm aware of the v8_linux_blink_rel failure, and will remove or suppress the
test on the Blink side before landing this.)

[Jakob Kummerow, 2017-01-28 00:35:36]

lgtm

[jbroman, 2017-01-28 04:12:09]

The CQ bit was checked by jbroman@chromium.org

[commit-bot: I haz the power, 2017-01-28 04:12:11]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-28 04:15:41]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-28 04:15:42]

Try jobs failed on following builders:
  v8_presubmit on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/33566)

[jbroman, 2017-01-28 05:19:09]

The CQ bit was checked by jbroman@chromium.org

[jbroman, 2017-01-28 05:19:10]

The patchset sent to the CQ was uploaded after l-g-t-m from
jkummerow@chromium.org
Link to the patchset: https://codereview.chromium.org/2658793004/#ps40001
(title: "merge with master")

[commit-bot: I haz the power, 2017-01-28 05:19:12]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-28 05:23:41]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-28 05:23:43]

Try jobs failed on following builders:
  v8_linux64_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel_ng/builds/20073)

[jbroman, 2017-01-28 05:33:46]

The CQ bit was checked by jbroman@chromium.org

[commit-bot: I haz the power, 2017-01-28 05:33:50]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-28 05:52:05]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1485581626886170,
"parent_rev": "851ef4677a460e464580009b94ee52d1dbf85d28", "commit_rev":
"bf511b426ee5d65976e1b87c7bac134585f0fc9f"}

[commit-bot: I haz the power, 2017-01-28 05:52:09]

Description was changed from

==========
ValueSerializer: Support efficiently reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=chromium:686159
==========

to

==========
ValueSerializer: Support efficiently reading and writing one-byte strings.

memcpy is faster than UTF-8 encoding/decoding. This yields 10-20% wins on
serializing and deserializing long ASCII strings, according to
blink_perf.bindings -- and these are already in a fast path where the entire
string is known to be ASCII (but this has to be checked). The win may be
larger for strings in Latin-1 but not ASCII (though I suspect this is an
uncommon case).

A change is also made to make ValueSerializerTest.EncodeTwoByteStringUsesPadding
survive wire format version number changes.

This is the first of a series of wire format changes from the previous Blink
format. The deserializer continues to be able to read the old format, but
Chromium M56 will no longer be able to read the messages written by this, in
M58.

BUG=chromium:686159

Review-Url: https://codereview.chromium.org/2658793004
Cr-Commit-Position: refs/heads/master@{#42753}
Committed:
https://chromium.googlesource.com/v8/v8/+/bf511b426ee5d65976e1b87c7bac134585f...
==========

[commit-bot: I haz the power, 2017-01-28 05:52:10]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/v8/v8/+/bf511b426ee5d65976e1b87c7bac134585f...