kylefang/react-native
1
0
Fork 0
mirror of https://github.com/zhigang1992/react-native.git synced 2026-04-02 09:21:44 +08:00
Code Issues Packages Projects Releases Wiki Activity

seek & read RAM Bundle

Browse Source 
Summary: For RAM bundling we don't want to hold the entire bundle in memory as that approach doesn't scale. Instead we want to seek and read individual sections as they're required. This rev does that by detecting the type of bundle we're dealing with by reading the first 4 bytes of it. If we're dealing with a RAM Bundle we bail loading.

Reviewed By: javache

Differential Revision: D3026205

fb-gh-sync-id: dc4c745d6f00aa7241203899e5ba136915efa6fe
shipit-source-id: dc4c745d6f00aa7241203899e5ba136915efa6fe
This commit is contained in:
Martín Bigio
2016-03-17 10:34:46 -07:00
committed by Facebook Github Bot 9
parent 4c7c365623
commit dd2415df73
4 changed files with 157 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
React/Base/RCTJavaScriptLoader.m
View File

@@ -15,6 +15,10 @@
#import "RCTUtils.h"
#import "RCTPerformanceLogger.h"
#include <sys/stat.h>
uint32_t const RCTRAMBundleMagicNumber = 0xFB0BD1E5;
@implementation RCTJavaScriptLoader
RCT_NOT_IMPLEMENTED(- (instancetype)init)
@@ -34,13 +38,48 @@ RCT_NOT_IMPLEMENTED(- (instancetype)init)
// Load local script file
if (scriptURL.fileURL) {
NSString *filePath = scriptURL.path;
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSError *error = nil;
NSData *source = [NSData dataWithContentsOfFile:filePath
options:NSDataReadingMappedIfSafe
error:&error];
RCTPerformanceLoggerSet(RCTPLBundleSize, source.length);
NSData *source = nil;
// Load the first 4 bytes to check if the bundle is regular or RAM ("Random Access Modules" bundle).
// The RAM bundle has a magic number in the 4 first bytes `(0xFB0BD1E5)`.
// The benefit of RAM bundle over a regular bundle is that we can lazily inject
// modules into JSC as they're required.
FILE *bundle = fopen(scriptURL.path.UTF8String, "r");
if (!bundle) {
onComplete(RCTErrorWithMessage([NSString stringWithFormat:@"Error opening bundle %@", scriptURL.path]), source);
return;
}
uint32_t magicNumber;
if (fread(&magicNumber, sizeof(magicNumber), 1, bundle) != 1) {
fclose(bundle);
onComplete(RCTErrorWithMessage(@"Error reading bundle"), source);
return;
}
magicNumber = NSSwapLittleIntToHost(magicNumber);
int32_t sourceLength = 0;
if (magicNumber == RCTRAMBundleMagicNumber) {
source = [NSData dataWithBytes:&magicNumber length:sizeof(magicNumber)];
struct stat statInfo;
if (stat(scriptURL.path.UTF8String, &statInfo) != 0) {
error = RCTErrorWithMessage(@"Error reading bundle");
} else {
sourceLength = statInfo.st_size;
}
} else {
source = [NSData dataWithContentsOfFile:scriptURL.path
options:NSDataReadingMappedIfSafe
error:&error];
sourceLength = source.length;
}
RCTPerformanceLoggerSet(RCTPLBundleSize, sourceLength);
fclose(bundle);
onComplete(error, source);
});
return;