source: trip-planner-front/node_modules/@webassemblyjs/helper-wasm-section/esm/resize.js@ 76712b2

Last change on this file since 76712b2 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

  • Property mode set to 100644
File size: 2.8 KB
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1import { encodeU32 } from "@webassemblyjs/wasm-gen";
2import { getSectionMetadata, traverse, shiftSection } from "@webassemblyjs/ast";
3import { overrideBytesInBuffer } from "@webassemblyjs/helper-buffer";
4export function resizeSectionByteSize(ast, uint8Buffer, section, deltaBytes) {
5 var sectionMetadata = getSectionMetadata(ast, section);
6
7 if (typeof sectionMetadata === "undefined") {
8 throw new Error("Section metadata not found");
9 }
10
11 if (typeof sectionMetadata.size.loc === "undefined") {
12 throw new Error("SectionMetadata " + section + " has no loc");
13 } // keep old node location to be overriden
14
15
16 var start = sectionMetadata.size.loc.start.column;
17 var end = sectionMetadata.size.loc.end.column;
18 var newSectionSize = sectionMetadata.size.value + deltaBytes;
19 var newBytes = encodeU32(newSectionSize);
20 /**
21 * update AST
22 */
23
24 sectionMetadata.size.value = newSectionSize;
25 var oldu32EncodedLen = end - start;
26 var newu32EncodedLen = newBytes.length; // the new u32 has a different encoded length
27
28 if (newu32EncodedLen !== oldu32EncodedLen) {
29 var deltaInSizeEncoding = newu32EncodedLen - oldu32EncodedLen;
30 sectionMetadata.size.loc.end.column = start + newu32EncodedLen;
31 deltaBytes += deltaInSizeEncoding; // move the vec size pointer size the section size is now smaller
32
33 sectionMetadata.vectorOfSize.loc.start.column += deltaInSizeEncoding;
34 sectionMetadata.vectorOfSize.loc.end.column += deltaInSizeEncoding;
35 } // Once we hit our section every that is after needs to be shifted by the delta
36
37
38 var encounteredSection = false;
39 traverse(ast, {
40 SectionMetadata: function SectionMetadata(path) {
41 if (path.node.section === section) {
42 encounteredSection = true;
43 return;
44 }
45
46 if (encounteredSection === true) {
47 shiftSection(ast, path.node, deltaBytes);
48 }
49 }
50 });
51 return overrideBytesInBuffer(uint8Buffer, start, end, newBytes);
52}
53export function resizeSectionVecSize(ast, uint8Buffer, section, deltaElements) {
54 var sectionMetadata = getSectionMetadata(ast, section);
55
56 if (typeof sectionMetadata === "undefined") {
57 throw new Error("Section metadata not found");
58 }
59
60 if (typeof sectionMetadata.vectorOfSize.loc === "undefined") {
61 throw new Error("SectionMetadata " + section + " has no loc");
62 } // Section has no vector
63
64
65 if (sectionMetadata.vectorOfSize.value === -1) {
66 return uint8Buffer;
67 } // keep old node location to be overriden
68
69
70 var start = sectionMetadata.vectorOfSize.loc.start.column;
71 var end = sectionMetadata.vectorOfSize.loc.end.column;
72 var newValue = sectionMetadata.vectorOfSize.value + deltaElements;
73 var newBytes = encodeU32(newValue); // Update AST
74
75 sectionMetadata.vectorOfSize.value = newValue;
76 sectionMetadata.vectorOfSize.loc.end.column = start + newBytes.length;
77 return overrideBytesInBuffer(uint8Buffer, start, end, newBytes);
78}
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