labath wrote:
I'm currently optimizing our data formatters for some fairly complex data
structures, and I've ran into something I don't understand. My DAP packet
sequence for a hover request consists of two (mostly redundant) packets:
```
-->
Content-Length: 114
{
"arguments": {
"context": "hover",
"expression": "v",
"frameId": 524288
},
"command": "evaluate",
"seq": 21,
"type": "request"
}
<--
Content-Length: 1830
{
"body": {
"result": "(std::vector<int>) v = size=121 {\n [0] = 1\n [1] = 2\n [2] =
3\n [3] = 4\n [4] = 5\n [5] = 6\n [6] = 7\n [7] = 77\n [8] = 3\n [9] =
33\n [10] = 54\n [11] = 5\n [12] = 53\n [13] = 523\n [14] = 532\n [15] =
53\n [16] = 3535\n [17] = 53\n [18] = 2235\n [19] = 352\n [20] = 35\n
[21] = 352\n [22] = 532\n [23] = 532\n [24] = 53\n [25] = 35523\n [26] =
523\n [27] = 532\n [28] = 523\n [29] = 523\n [30] = 523\n [31] = 523\n
[32] = 235\n [33] = 523\n [34] = 532\n [35] = 532\n [36] = 523\n [37] =
523\n [38] = 53\n [39] = 312\n [40] = 5\n [41] = 346\n [42] = 4256\n [43]
= 346\n [44] = 234\n [45] = 632\n [46] = 523\n [47] = 6\n [48] = 246\n
[49] = 54\n [50] = 672\n [51] = 67\n [52] = 2457\n [53] = 234\n [54] =
7524\n [55] = 7\n [56] = 4376\n [57] = 23467\n [58] = 432\n [59] = 6\n
[60] = 2347\n [61] = 5435\n [62] = 2\n [63] = 346\n [64] = 4536\n [65] =
34\n [66] = 53\n [67] = 324\n [68] = 645\n [69] = 645\n [70] = 456\n [71]
= 75\n [72] = 343\n [73] = 3\n [74] = 4\n [75] = 654\n [76] = 3545\n [77]
= 5\n [78] = 4\n [79] = 435\n [80] = 5\n [81] = 345\n [82] = 54\n [83] =
435\n [84] = 43\n [85] = 245\n [86] = 54\n [87] = 32\n [88] = 4565\n [89]
= 65\n [90] = 54\n [91] = 43\n [92] = 54\n [93] = 535\n [94] = 3\n [95] =
4\n [96] = 5\n [97] = 5\n [98] = 65\n [99] = 1342\n [100] = 43657\n [101]
= 67856\n [102] = 523\n [103] = 4\n [104] = 534\n [105] = 576\n [106] =
57\n [107] = 46\n [108] = 24\n [109] = 6\n [110] = 568\n [111] = 5658\n
[112] = 76\n [113] = 42\n [114] = 634\n [115] = 8\n [116] = 54657\n [117]
= 6\n [118] = 4\n [119] = 8356\n [120] = 75\n}",
"type": "std::vector<int>",
"variablesReference": 8
},
"command": "evaluate",
"request_seq": 21,
"seq": 0,
"success": true,
"type": "response"
}
-->
Content-Length: 86
{
"arguments": {
"variablesReference": 8
},
"command": "variables",
"seq": 22,
"type": "request"
}
<--
Content-Length: 17549
{
"body": {
"variables": [
{
"$__lldb_extensions": {
"value": "1"
},
"evaluateName": "v._M_impl._M_start->[0]",
"name": "[0]",
"type": "int",
"value": "1",
"variablesReference": 0
},
// ...
{
"$__lldb_extensions": {
"value": "75"
},
"evaluateName": "v._M_impl._M_start->[120]",
"name": "[120]",
"type": "int",
"value": "75",
"variablesReference": 0
}
]
},
"command": "variables",
"request_seq": 22,
"seq": 0,
"success": true,
"type": "response"
}
```
The first response contains the contents of the formatted variable (a vector,
in this example) as a string, while the second one contains the same data in a
structured form. Looking at the history, I've found this PR, which seems to
indicate that the first packet is necessary in order to provide the contents of
data structure in the hover window. However, that does not appear to match what
I'm seeing:
>From what I can tell by this screenshot, the only part that VSCode uses from
>the first response is the first line (which it uses as the "summary" of the
>value, while the rest of the data (the vector contents) comes from the second
>response.
The first response is problematic for me, because that output can contain a lot
more information (if the vector contained structures rather than ints, those
structures would get expanded recursively) than what's displayed on the screen,
which makes the popups slower than necessary. From what I'm seeing, it would be
ideal to remove the expansion in the first response completely (which would
essentially amount to reverting this PR), given that the information is already
contained in the second one. However, I am assuming there is a reason for why
that code exists -- but then I don't understand why does my experience (and
screenshots) differ so much from the screenshots on this PR. Could something
have changed (over the last 4 months) in how VSCode behaves that would mean
this PR is not necessary?
Can anyone shed any light on this?
https://github.com/llvm/llvm-project/pull/77026
_______________________________________________
lldb-commits mailing list
lldb-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
