I'm doing a simple transaction with a single transfer instruction for 0,1 SOL from one account to another. Then I want to get the transaction data and use it to verify the data it carries - in this case that a transfer has been made for 0,1 SOL.
I use getTransaction with the tx signature and get a response like this:
{
message: Message {
header: {
numReadonlySignedAccounts: 0,
numReadonlyUnsignedAccounts: 1,
numRequiredSignatures: 1
},
accountKeys: [ [PublicKey], [PublicKey], [PublicKey] ],
recentBlockhash: '9S44wiNxXZSdP5VTG6nvaumUJBiUW1DGUXmhVfuhwTMh',
instructions: [ [Object] ],
indexToProgramIds: Map(1) { 2 => [PublicKey] }
},
signatures: [
'8ykRq1XtgrtymXVkVhsWjaDrid5FkKzRPJrarzJX9a6EArbEUYMrst6vVC6TydDRG4sagSciK6pP5Lw9ZDnt3RD'
]
}
So, I dig into message.instructions and find the following object:
{ accounts: [ 0, 1 ], data: '3Bxs411Dtc7pkFQj', programIdIndex: 2 }
Ok, so data is the base58-encoded string '3Bxs411Dtc7pkFQj'. I decode that from base58 (using bs58), but that only gives me a Uint8Array, which I am not really sure how to convert into a JS object.
I can see in the tx in Solscan that the data information is decoded into hex:
And I can also get this info in my script:
---> Instructions:
{ accounts: [ 0, 1 ], data: '3Bxs411Dtc7pkFQj', programIdIndex: 2 }
---> Instructions Data:
3Bxs411Dtc7pkFQj
0200000000e1f50500000000
-----
But not sure what to do next. How do I get the actual amount data out of it.
So, I guess the question is: How to decode the instruction data into a JS object?
So, for your second question:
To know how to deserialize the array returned from the bs58 decoding you need to know how the sender serialized the instruction.
I was redirected to solana.stackexchange.com and there I found the answer. Basically, I could use getParsedTransaction instead of just getTransaction.
The parsed function would give me exactly what I need, since the instructions prop is an array containing one object (in my case), which looks like this:
{
parsed: {
info: {
destination: 'foo',
lamports: 100000000,
source: 'bar'
},
type: 'transfer'
},
// ... other props
}
Related
I am trying to boil down a pretty complicated problem into its essence so I can get some help on how to model or architect it. Here it goes.
Say we are compiling functions in this order:
function test() {
sum(mul(2, 3), mul(3, 4))
}
function sum(a, b) {
return a + b
}
function mul(a, b) {
return a * b
}
We end up with an AST something like this:
{
type: 'Program',
blocks: [
{
type: 'Function',
name: 'test',
args: [],
body: [
{
type: 'Call',
function: 'sum',
args: [
{
type: 'Call',
function: 'mul',
...
},
...
]
}
]
},
{
type: 'Function',
name: 'mul',
args: ...,
body: ...
},
{
type: 'Function',
name: 'sum',
args: ...,
body: ...
}
]
}
Now we start compiling this AST into more easily manipulated objects, with direct pointers to functions and such. The final result might look like this:
{
type: 'Program',
blocks: [
{
type: 'Function',
name: 'test',
args: [],
body: [
{
type: 'Call',
pointer: 2,
args: [
{
type: 'Call',
pointer: 1,
...
},
...
]
}
]
},
{
type: 'Function',
name: 'mul',
args: ...,
body: ...
},
{
type: 'Function',
name: 'sum',
args: ...,
body: ...
}
]
}
The main difference is that the "final" version has a pointer to the index where the function is defined. This is a very rough sketch. The reality would be there could be multiple passes required to resolve some context sensitivity, and so you end up with multiple partial/intermediate data structures in the transition from the AST to the final compiled object.
How do you make types to deal with this situation? The ideal is that there is an "initial" and a "final" type. The reality is that on our first pass, we have a "placeholder type" for the function calls, which we can't resolve until we have completed our first pass. So on the first pass, we have:
function: String
On the second pass we change it to:
pointer: Int
How do you reconcile this? How do you architect the algorithm so as to allow for these "placeholder" types for the final data structure?
I have tried searching the web for these sorts of topics but haven't found anything:
partial types
intermediate types
placeholder types
virtual types
temporary types
transitional types
how to have temporary placeholders in data structures
etc.
Create a hashmap.
In a first pass write name/index pairs to the hashmap without modifying the AST itself. For the example that would result in this hashmap (represented in JSON format):
{
"mul": 1,
"sum": 2
}
In a second pass you can use the hashmap to replace references to the keys of this hashmap with a pointer property that gets the corresponding value.
I would suggest not trying to understand how to store intermediate data types, but understanding how to store "references" or "holes". Go look up how a typical serialization/deserialization algorithm works (especially one that can deal with something like repeated substructure or circular references): http://www.dietmar-kuehl.de/mirror/c++-faq/serialization.html
It may give you helpful ideas.
I have a JSON structure something like this:
{
Id: 1
Data: [
{
X: 1,
Content: [...]
},
{
X: 2,
Content: [...]
},
]
}
Where Content can be very large byte arrays. The problem I have is that serialising and deserializing this structure using JSON.NET takes ups a large amount of memory on the LOH.
Is there some way I can WebAPI to stream the byte arrays to files?
The only other solution I can see is abandon JSON and use multipart/form-data but this seems kind of ugly, or is there some other way?
I have an array of objects from which I need to pass each object separately into async method (process behind is handled with Promise and then converted back to Observable via Observable.fromPromise(...) - this way is needed because the same method is used in case just single object is passed anytime; the process is saving objects into database). For example, this is an array of objects:
[
{
"name": "John",
...
},
{
"name": "Anna",
...
},
{
"name": "Joe",,
...
},
{
"name": "Alexandra",
...
},
...
]
Now I have the method called insert which which inserts object into database. The store method from database instance returns newly created id. At the end the initial object is copied and mapped with its new id:
insert(user: User): Observable<User> {
return Observable.fromPromise(this.database.store(user)).map(
id => {
let storedUser = Object.assign({}, user);
storedUser.id = id;
return storedUser;
}
);
}
This works well in case I insert single object. However, I would like to add support for inserting multiple objects which just call the method for single insert. Currently this is what I have, but it doesn't work:
insertAll(users: User[]): Observable<User[]> {
return Observable.forkJoin(
users.map(user => this.insert(user))
);
}
The insertAll method is inserting users as expected (or something else filled up the database with that users), but I don't get any response back from it. I was debugging what is happening and seems that forkJoin is getting response just from first mapped user, but others are ignored. Subscription to insertAll does not do anything, also there is no any error either via catch on insertAll or via second parameter in subscribe to insertAll.
So I'm looking for a solution where the Observable (in insertAll) would emit back an array of new objects with users in that form:
[
{
"id": 1,
"name": "John",
...
},
{
"id": 2,
"name": "Anna",
...
},
{
"id": 3,
"name": "Joe",,
...
},
{
"id": 4,
"name": "Alexandra",
...
},
...
]
I would be very happy for any suggestion pointing in the right direction. Thanks in advance!
To convert from array to observable you can use Rx.Observable.from(array).
To convert from observable to array, use obs.toArray(). Notice this does return an observable of an array, so you still need to .subscribe(arr => ...) to get it out.
That said, your code with forkJoin does look correct. But if you do want to try from, write the code like this:
insertAll(users: User[]): Observable<User[]> {
return Observable.from(users)
.mergeMap(user => this.insert(user))
.toArray();
}
Another more rx like way to do this would be to emit values as they complete, and not wait for all of them like forkJoin or toArray does. We can just omit the toArray from the previous example and we got it:
insertAll(users: User[]): Observable<User> {
return Observable.from(users)
.mergeMap(user => this.insert(user));
}
As #cartant mentioned, the problem might not be in Rx, it might be your database does not support multiple connections. In that case, you can replace the mergeMap with concatMap to make Rx send only 1 concurrent request:
insertAll(users: User[]): Observable<User[]> {
return Observable.from(users)
.concatMap(user => this.insert(user))
.toArray(); // still optional
}
I'm trying to test a small Sinatra app using rspec. I want to pass a rather complex payload and am running into issues i do not understand: my payload contains an array of hashes. When I run the actual application this will work as expected, yet when I use the post helper to run my tests, the array will contain a merged hash:
post(
"/#{bot}/webhook",
sessionId: "test-session-#{session_counter}",
result: {
contexts: [
{ some: 'fixture' },
{ name: 'generic', parameters: { facebook_sender_id: 'zuck-so-cool' } }
]
}
)
In the sinatra handler I use params to access this payload:
post '/:bot/webhook' do |bot|
do_something_with(params)
end
When I now look at the structure of params when running the test suite, I will see the following structure:
[{"some" => "fixture", "name" => "generic", "parameters" => {"facebook_sender_id" => "zuck-so-cool"}}]
which I do not really understand. Is this a syntax issue (me being a ruby noob), am I using params wrong, or is this a bug?
EDIT: So i found out this is an "issue" with the way that Rack::Test will serialize the given payload when not specifying how to (i.e. as form data). If I pass JSON and pass the correct headers it will do what I expect it to do:
post(
"/#{bot}/webhook",
{
sessionId: "test-session-#{session_counter}",
result: {
contexts: [
{ some: 'fixture' },
{ name: 'generic', parameters: { facebook_sender_id: 'zuck-so-cool' } }
]
}
}.to_json,
{ 'HTTP_ACCEPT' => 'application/json', 'CONTENT_TYPE' => 'application/json' }
)
Still I am unsure of this is an issue with the passed data structure not being possible to be serialized into form data or if this is a bug in the way that Rack::Test serializes data.
Looking at the relevant portion of the specs it looks like this is is expected behavior.
Is there a way in RxJs to perform two api calls where the second requires data from the first and return a combined result as a stream? What I'm trying to do is call the facebook API to get a list of groups and the cover image in various sizes. Facebook returns something like this:
// call to facebook /1234 to get the group 1234, cover object has an
// image in it, but only one size
{ id: '1234', cover: { id: '9999' } }
// call to facebook /9999 to get the image 9999 with an array
// with multiple sizes, omitted for simplicity
{ images: [ <image1>, <image2>, ... ] }
// desired result:
{ id: '1234', images: [ <image1>, <image2>, ... ] }
So I have this:
var result = undefined;
rxGroup = fbService.observe('/1234');
rxGroup.subscribe(group => {
rxImage = fbService.observe(`/${group.cover.id}`);
rxImage.subscribe(images => {
group.images = y;
result = group;
}
}
I want to create a method that accepts a group id and returns an Observable that will have the combined group + images (result here) in the stream. I know I can create my own observable and call the next() function in there where I set 'result' above, but I'm thinking there has to be an rx-way to do this. select/map lets me transform, but I don't know how to shoe-in the results from another call. when/and/then seems promising, but also doesn't look like it supports something like that. I could map and return an observable, but the caller would then have to do two subscribes.
Looks like flatMap is the way to go (fiddle). It is called like subscribe and gives you a value from a stream. You return an observable from that and it outputs the values from all the created observables (one for for each element in the base stream) into the resulting stream.
var sourceGroup = { // result of calling api /1234
id: '1234',
cover: {
id: '9999'
}
};
var sourceCover = { // result of calling api /9999
id: '9999',
images: [{
src: 'image1x80.png'
}, {
src: 'image1x320.png'
}]
};
var rxGroup = Rx.Observable.just(sourceGroup);
var rxCombined = rxGroup.flatMap(group =>
Rx.Observable.just(sourceCover)
.map(images => ({
id: group.id,
images: images.images
}))
)
rxCombined.subscribe(x =>
console.log(JSON.stringify(x, null, 2)));
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/4.1.0/rx.all.min.js"></script>
Result:
{
"id": "1234",
"images": [
{
"src": "image1x80.png"
},
{
"src": "image1x320.png"
}
]
}
You should use concatMap instead of flatMap, it will preserve the order of the source emissions.