Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Issue #12538 suggested that maybe Alternator shouldn't bother reporting an
invalid table name in item operations like PutItem, and that it's enough
to report that the table doesn't exist. But the test added in this patch
shows that DynamoDB, like Alternator, reports the invalid table name in
this case - not just that the table doesn't exist.
That should make us think twice before acting on issue #12538. If we do
what this issue recommended, this test will need to be fixed (e.g., to
accept as correct both types of errors).
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#12608
This reverts commit 8e892426e2 and fixes
the code in a different way:
That commit moved the scylla_inject_error function from
test/alternator/util.py to test/cql-pytest/util.py and renamed
test/alternator/util.py. I found the rename confusing and unnecessary.
Moreover, the moved function isn't even usable today by the test suite
that includes it, cql-pytest, because it lacks the "rest_api" fixture :-)
so test/cql-pytest/util.py wasn't the right place for it anyway.
test/rest_api/rest_util.py could have been a good place for this function,
but there is another complication: Although the Alternator and rest_api
tests both had a "rest_api" fixture, it has a different type, which led
to the code in rest_api which used the moved function to have to jump
through hoops to call it instead of just passing "rest_api".
I think the best solution is to revert the above commit, and duplicate
the short scylla_inject_error() function. The duplication isn't an
exact copy - the test/rest_api/rest_util.py version now accepts the
"rest_api" fixture instead of the URL that the Alternator version used.
In the future we can remove some of this duplication by having some
shared "library" code but we should do it carefully and starting with
agreeing on the basic fixtures like "rest_api" and "cql", without that
it's not useful to share small functions that operate on them.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#11275
Move scylla_inject_error from alternator/ to cql-pytest/ so it
can be reached from various tests dirs. alternator/util.py is
renamed to alternator/alternator_util.py to avoid name shadowing.
This patch adds several more tests for Alternator's UpdateItem operation.
These tests verify a few simple cases that, surprisingly, never had test
coverage. The new tests pass (on both DynamoDB and Alternator) so did not
expose any bug.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#11025
In DynamoDB one can retrieve only a subset of the attributes using the
AttributesToGet or ProjectionExpression paramters to read requests.
Neither allows an empty list of attributes - if you don't want any
attributes, you should use Select=COUNT instead.
Currently we correctly refuse an empty ProjectionExpression - and have
a test for it:
test_projection_expression.py::test_projection_expression_toplevel_syntax
However, Alternator is missing the same empty-forbidding logic for
AttributesToGet. An empty AttributesToGet is currently allowed, and
basically says "retrieve everything", which is sort of unexpected.
So this patch adds the missing logic, and the missing test (actually
two tests for the same thing - one using GetItem and the other Query).
Fixes#10332
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220405113700.9768-1-nyh@scylladb.com>
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
The "ADD" operator in UpdateItem's AttributeUpdates supports a number of
types (numbers, sets and strings), should result in a ValidationException
if the attribute's existing type is different from the type of the
operand - e.g., trying to ADD a number to an attribute which has a set
as a value.
So far we only had partial testing for this (we tested the case where
both operands are sets, but of different types) so this patch adds the
missing tests. The new tests pass (on both Alternator and DynamoDB) -
we don't have a bug there.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20211213195023.1415248-1-nyh@scylladb.com>
In the DynamoDB API, UpdateItem's AttributeUpdates parameter (the older
syntax, which was superseded by UpdateExpression) has a DELETE operation
that can do two different things: It can delete an attribute, or it can
delete elements from a set. Before this patch we only implemented the
first feature, and this patch implements the second.
Note that unlike the ordinary delete, the second feature - set subtraction -
is a read-modify-write operation. This is not only because of Alternator's
serialization (as JSON strings, not CRDTs) - but also fundementally because
of the API's guarantees - e.g., the operation is supposed to fail if the
attribute's existing value is *not* a set of the correct type, so it
needs to read the old value.
The test for this feature begins to pass, so its "xfail" mark is
removed. After this, all tests in test/alternator/test_item.py pass :-)
Fixes#5864.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20211103151206.157184-1-nyh@scylladb.com>
In UpdateItem's AttributeUpdates (old-style parameter) we were missing
support for the ADD operation - which can increment a number, or add
items to sets (or to lists, even though this fact isn't documented).
This patch adds this feature, and the test for it begins to pass so its
"xfail" marker is removed.
Fixes#5893
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Since May 2020 empty strings are allowed in DynamoDB as attribute values
(see announcment in [1]). However, they are still not allowed as keys.
We had tests that they are not allowed in keys of LSI or GSI, but missed
tests that they are not allowed as keys (partition or sort key) of base
tables. This patch add these missing tests.
These tests pass - we already had code that checked for empty keys and
generated an appropriate error.
Note that for compatibility with DynamoDB, Alternator will forbid empty
strings as keys even though Scylla *does* support this possibility
(Scylla always supported empty strings as clustering key, and empty
partition keys will become possible with issue #9352).
[1] https://aws.amazon.com/about-aws/whats-new/2020/05/amazon-dynamodb-now-supports-empty-values-for-non-key-string-and-binary-attributes-in-dynamodb-tables/
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20211003122842.471001-1-nyh@scylladb.com>
The tests in this patch verify that null characters are valid characters
inside string and bytes (blob) attributes in Alternator. The tests
verify this for both key attributes and non-key attributes (since those
are serialized differently, it's important to check both cases).
The tests pass on both DynamoDB and Alternator - confirming that we
don't have a bug in this area.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210824163442.186881-1-nyh@scylladb.com>
In the existing code, the variable "attrs_to_get" is a list of top-level
attributes to fetch for an item. It is used to implement features like
ProjectionExpression or AttributesToGet in GetItem and other places.
However, to support attribute paths (e.g., a.b.c[2]) in ProjectionExpression,
i.e., issue #5024, we need more than that. We still need to know the top-
level attribute "a", because this is the granularity we have in the Scylla
table (all the content inside "a" is serialized as a single JSON); But we
also need to remember exactly which parts *inside* "a" we will need to
extract and return.
So in this patch we add a new type, "attrs_to_get", which is more than
just a list of top-level attributes. Instead, it is a *map*, whose keys
are the top-level attributes, and the value for each of them is a
"hierarchy_filter", an object which describes which part of the attribute
is needed.
This patch includes the code which converts the AttributesToGet and
ProjectionExpression into the new attrs_to_get structure. During this
conversion, we recognize two kinds of errors which DynamoDB complains
about: We recognize "overlapping" attributes (e.g., requesting both
a.b and a.b.c) and "conflicting" attributes (e.g, requesting both
a.b and a[1]). After this, two xfailing tests we had for detecting
these overlap and conflicts finally pass and their "xfail" label is
removed.
After this patch, we have the attrs_to_get object which can allow us
to filter only the requested pieces of the top-level attributes, but
we don't use it yet - so this patch is not enough for complete support
of attribute paths in ProjectionExpression. We will complete this
support in the next patch.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
In the DynamoDB API, expressions (e.g., ConditionExpression and many more)
may contain references to column names ("#name") or to values (":val")
given in a separate part of the request - ExpressionAttributeNames and
ExpressionAttributeValues respectively.
Before this patch, we resolved these references as part of the expression's
evaluation. This approach had two downsides:
1. It often misdiagnosed (both false negatives and false positives) cases
of unused names and values in expressions. We already had two xfailing
tests with examples - which pass after this patch. This patch also
adds two additional tests, which failed before this patch and pass
with it.
2. In one of the following patches we will add support for FilterExpression,
where the same expression is used repeatedly on many items. It is a waste
(as well as makes the code uglier) to resolve the same references again
and again each time the expression is evaluated. We should be able
to do it just once.
So this patch introduces an intermediate step between parsing and evaluating
an expression - "resolving" the expression. The new resolve_*() functions
modify the already parsed expression, replacing references to attribute
names and constant values by the actual names and values taken from the
request. The resolve_*() functions also keep track which references were
used, making it very easy to check (as DynamoDB does) if there are any
unused names or values, before starting the evaluation.
The interface of evaluate() functions become much simpler - they no longer
need to know the original request (which was previously needed for
ExpressionAttributeNames/Values), the table's schema (which was previously
needed only for some error checking), keep track of which references were
used. This simplification is helpful for using the expressions in contexts
where these things (request and schema) are no longer conveniently available,
namely in FilterExpression.
A small side-benefit of this patch is that it moves a bit of code, which
handled resolving of references in expressions, from executor.cc to
expressions.cc. This is just the first step in a bigger effort to
reduce the size of executor.cc by moving code to smaller source files.
There is no attempt in this patch to move as much code as we can.
We will move more code in a separate patch in this series.
Fixes#6572.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Although Python 2 is deprecated, some systems today still have "python"
and "pytest" pointing to Python 2, so it would be convenient for the
Alternator tests to work on both Python 2 and 3 if it's not too much
of an effort.
And it really isn't too much of an effort - they all work on both versions
except for one problem introduced in the previous test patch: The syntax b''
for an empty byte array works correctly on Python 3 but incorrectly on
Python 2: In Python 2, b'' is just a normal empty string, not byte array,
which confuses Boto3 which refuses to accept a string as a value for a
byte-array key.
The trivial fix is to replace b'' by bytearray('', 'utf-8').
Uglier, but works as expected on both Python 2 and 3.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200519214321.25152-1-nyh@scylladb.com>
To make the tests in alternator-test runnable by test.py, we need to
move the directory alternator-test/ to test/alternator, because test.py
only looks for tests in subdirectories of test/. Then, we need to create
a test/alternator/suite.yaml saying that this test directory is of type
"Run", i.e., it has a single run script "run" which runs all its tests.
The "run" script had to be slightly modified to be aware of its new
location relative to the source directory.
To run the Alternator tests from test.py, do:
./test.py --mode dev alternator
Note that in this version, the "--mode" has no effect - test/alternator/run
always runs the latest compiled Scylla, regardless of the chosen mode.
The Alternator tests can still be run manually and individually against
a running Scylla or DynamoDB as before - just go to the test/alternator
directory (instead of alternator-test previously) and run "pytest" with
the desired parameters.
Fixes#6046
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
