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 коммит произвёл Facebook Github Bot 9
Родитель 4c7c365623
Коммит dd2415df73
4 изменённых файлов: 157 добавлений и 50 удалений

Просмотреть файл

@ -11,6 +11,8 @@
#import "RCTBridgeDelegate.h"
extern uint32_t const RCTRAMBundleMagicNumber;
@class RCTBridge;
/**

Просмотреть файл

@ -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;

Просмотреть файл

@ -18,6 +18,7 @@
#import "RCTBridge+Private.h"
#import "RCTDefines.h"
#import "RCTDevMenu.h"
#import "RCTJavaScriptLoader.h"
#import "RCTLog.h"
#import "RCTProfile.h"
#import "RCTPerformanceLogger.h"
@ -35,6 +36,7 @@ static NSString *const RCTJSCProfilerEnabledDefaultsKey = @"RCTJSCProfilerEnable
typedef struct ModuleData
{
uint32_t offset;
uint32_t length;
uint32_t lineNo;
} ModuleData;
@ -101,7 +103,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
RCTJavaScriptContext *_context;
NSThread *_javaScriptThread;
NSData *_bundle;
FILE *_bundle;
JSStringRef _bundleURL;
CFMutableDictionaryRef _jsModules;
}
@ -368,6 +370,7 @@ static void RCTInstallJSCProfiler(RCTBridge *bridge, JSContextRef context)
if (_jsModules) {
CFRelease(_jsModules);
fclose(_bundle);
}
#if RCT_DEV
@ -519,19 +522,33 @@ static void RCTInstallJSCProfiler(RCTBridge *bridge, JSContextRef context)
sourceURL:(NSURL *)sourceURL
onComplete:(RCTJavaScriptCompleteBlock)onComplete
{
// Check if it's a `RAM bundle` ("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.
static const uint32_t ramBundleMagicNumber = 0xFB0BD1E5;
uint32_t magicNumber = *(uint32_t *)script.bytes;
if (magicNumber == ramBundleMagicNumber) {
script = [self loadRAMBundle:script];
}
RCTAssertParam(script);
RCTAssertParam(sourceURL);
// The RAM bundle has a magic number in the 4 first bytes `(0xFB0BD1E5)`.
uint32_t magicNumber = NSSwapLittleIntToHost(*((uint32_t *)script.bytes));
BOOL isRAMBundle = magicNumber == RCTRAMBundleMagicNumber;
if (isRAMBundle) {
NSError *error;
script = [self loadRAMBundle:sourceURL error:&error];
if (error) {
if (onComplete) {
onComplete(error);
}
return;
}
} else {
// JSStringCreateWithUTF8CString expects a null terminated C string.
// RAM Bundling already provides a null terminated one.
NSMutableData *nullTerminatedScript = [NSMutableData dataWithCapacity:script.length + 1];
[nullTerminatedScript appendData:script];
[nullTerminatedScript appendBytes:"" length:1];
script = nullTerminatedScript;
}
_bundleURL = JSStringCreateWithUTF8CString(sourceURL.absoluteString.UTF8String);
__weak RCTJSCExecutor *weakSelf = self;
@ -544,14 +561,8 @@ static void RCTInstallJSCProfiler(RCTBridge *bridge, JSContextRef context)
RCTPerformanceLoggerStart(RCTPLScriptExecution);
// JSStringCreateWithUTF8CString expects a null terminated C string
NSMutableData *nullTerminatedScript = [NSMutableData dataWithCapacity:script.length + 1];
[nullTerminatedScript appendData:script];
[nullTerminatedScript appendBytes:"" length:1];
JSValueRef jsError = NULL;
JSStringRef execJSString = JSStringCreateWithUTF8CString(nullTerminatedScript.bytes);
JSStringRef execJSString = JSStringCreateWithUTF8CString(script.bytes);
JSStringRef jsURL = JSStringCreateWithCFString((__bridge CFStringRef)sourceURL.absoluteString);
JSValueRef result = JSEvaluateScript(strongSelf->_context.ctx, execJSString, NULL, jsURL, 0, &jsError);
JSStringRelease(jsURL);
@ -635,7 +646,7 @@ static int streq(const char *a, const char *b)
return strcmp(a, b) == 0;
}
static void freeModuleData(__unused CFAllocatorRef allocator, void *ptr)
static void freeModule(__unused CFAllocatorRef allocator, void *ptr)
{
free(ptr);
}
@ -648,7 +659,19 @@ static uint32_t readUint32(const void **ptr) {
return data;
}
- (NSData *)loadRAMBundle:(NSData *)script
static int readBundle(FILE *fd, size_t offset, size_t length, void *ptr) {
if (fseek(fd, offset, SEEK_SET) != 0) {
return 1;
}
if (fread(ptr, sizeof(uint8_t), length, fd) != length) {
return 1;
}
return 0;
}
- (void)registerNativeRequire
{
__weak RCTJSCExecutor *weakSelf = self;
_context.context[@"nativeRequire"] = ^(NSString *moduleName) {
@ -657,14 +680,18 @@ static uint32_t readUint32(const void **ptr) {
return;
}
ModuleData *moduleData = (ModuleData *)CFDictionaryGetValue(strongSelf->_jsModules, moduleName.UTF8String);
JSStringRef module = JSStringCreateWithUTF8CString((const char *)_bundle.bytes + moduleData->offset);
int lineNo = [moduleName isEqual:@""] ? 0 : moduleData->lineNo;
ModuleData *data = (ModuleData *)CFDictionaryGetValue(strongSelf->_jsModules, moduleName.UTF8String);
char bytes[data->length];
if (readBundle(strongSelf->_bundle, data->offset, data->length, bytes) != 0) {
RCTFatal(RCTErrorWithMessage(@"Error loading RAM module"));
return;
}
JSStringRef code = JSStringCreateWithUTF8CString(bytes);
JSValueRef jsError = NULL;
JSValueRef result = JSEvaluateScript(strongSelf->_context.ctx, module, NULL, strongSelf->_bundleURL, lineNo, NULL);
JSValueRef result = JSEvaluateScript(strongSelf->_context.ctx, code, NULL, strongSelf->_bundleURL, data->lineNo, NULL);
CFDictionaryRemoveValue(strongSelf->_jsModules, moduleName.UTF8String);
JSStringRelease(module);
JSStringRelease(code);
if (!result) {
dispatch_async(dispatch_get_main_queue(), ^{
@ -673,45 +700,82 @@ static uint32_t readUint32(const void **ptr) {
});
}
};
}
- (NSData *)loadRAMBundle:(NSURL *)sourceURL error:(NSError **)error
{
_bundle = fopen(sourceURL.path.UTF8String, "r");
if (!_bundle) {
*error = RCTErrorWithMessage([NSString stringWithFormat:@"Bundle %@ cannot be opened: %d", sourceURL.path, errno]);
return nil;
}
[self registerNativeRequire];
_bundle = script;
CFDictionaryKeyCallBacks keyCallbacks = { 0, NULL, NULL, NULL, (CFDictionaryEqualCallBack)streq, (CFDictionaryHashCallBack)strlen };
// once a module has been loaded free its space from the heap, remove it from the index and release the module name
CFDictionaryValueCallBacks valueCallbacks = { 0, NULL, (CFDictionaryReleaseCallBack)freeModuleData, NULL, NULL };
CFDictionaryKeyCallBacks keyCallbacks = { 0, NULL, (CFDictionaryReleaseCallBack)freeModule, NULL, (CFDictionaryEqualCallBack)streq, (CFDictionaryHashCallBack)strlen };
CFDictionaryValueCallBacks valueCallbacks = { 0, NULL, (CFDictionaryReleaseCallBack)freeModule, NULL, NULL };
_jsModules = CFDictionaryCreateMutable(NULL, 0, &keyCallbacks, &valueCallbacks);
const uint8_t *bytes = script.bytes;
uint32_t currentOffset = 4; // skip magic number
uint32_t currentOffset = sizeof(uint32_t); // skip magic number
uint32_t tableLength;
memcpy(&tableLength, bytes + currentOffset, sizeof(tableLength));
if (readBundle(_bundle, currentOffset, sizeof(tableLength), &tableLength) != 0) {
*error = RCTErrorWithMessage(@"Error loading RAM Bundle");
return nil;
}
tableLength = NSSwapLittleIntToHost(tableLength);
// offset where the code starts on the bundle
const uint32_t baseOffset = currentOffset + tableLength;
currentOffset += sizeof(uint32_t); // skip table length
// pointer to first byte out of the index
const uint8_t *endOfTable = bytes + baseOffset;
// base offset to add to every module's offset to skip the header of the RAM bundle
uint32_t baseOffset = 4 + tableLength;
// pointer to current position on table
const uint8_t *tablePos = bytes + 2 * sizeof(uint32_t); // skip magic number and table length
char tableStart[tableLength];
if (readBundle(_bundle, currentOffset, tableLength, tableStart) != 0) {
*error = RCTErrorWithMessage(@"Error loading RAM Bundle");
return nil;
}
while (tablePos < endOfTable) {
const char *moduleName = (const char *)tablePos;
void *tableCursor = tableStart;
void *endOfTable = tableCursor + tableLength;
while (tableCursor < endOfTable) {
uint32_t nameLength = strlen((const char *)tableCursor);
char *name = malloc(nameLength + 1);
if (!name) {
*error = RCTErrorWithMessage(@"Error loading RAM Bundle");
return nil;
}
strcpy(name, tableCursor);
// the space allocated for each module's metada gets freed when the module is injected into JSC on `nativeRequire`
ModuleData *moduleData = malloc(sizeof(ModuleData));
tablePos += strlen(moduleName) + 1; // null byte terminator
tableCursor += nameLength + 1; // null byte terminator
moduleData->offset = baseOffset + readUint32((const void **)&tablePos);
moduleData->lineNo = readUint32((const void **)&tablePos);
moduleData->offset = baseOffset + readUint32((const void **)&tableCursor);
moduleData->length = readUint32((const void **)&tableCursor);
moduleData->lineNo = readUint32((const void **)&tableCursor);
CFDictionarySetValue(_jsModules, moduleName, moduleData);
CFDictionarySetValue(_jsModules, name, moduleData);
}
uint32_t offset = ((ModuleData *)CFDictionaryGetValue(_jsModules, ""))->offset;
return [NSData dataWithBytesNoCopy:((char *) script.bytes) + offset length:script.length - offset freeWhenDone:NO];
ModuleData *startupData = ((ModuleData *)CFDictionaryGetValue(_jsModules, ""));
void *startupCode;
if (!(startupCode = malloc(startupData->length))) {
*error = RCTErrorWithMessage(@"Error loading RAM Bundle");
return nil;
}
if (readBundle(_bundle, startupData->offset, startupData->length, startupCode) != 0) {
*error = RCTErrorWithMessage(@"Error loading RAM Bundle");
return nil;
}
return [NSData dataWithBytesNoCopy:startupCode length:startupData->length freeWhenDone:YES];
}
RCT_EXPORT_METHOD(setContextName:(nonnull NSString *)name)

Просмотреть файл

@ -90,6 +90,7 @@ function buildModuleTable(buffers) {
// entry:
// - module_id: NUL terminated utf8 string
// - module_offset: uint_32 offset into the module string
// - module_length: uint_32 length in bytes of the module
// - module_line: uint_32 line on which module starts on the bundle
const numBuffers = buffers.length;
@ -107,6 +108,7 @@ function buildModuleTable(buffers) {
Buffer(i === 0 ? MAGIC_STARTUP_MODULE_ID : id, 'utf8'),
nullByteBuffer,
uInt32Buffer(currentOffset),
uInt32Buffer(length),
uInt32Buffer(currentLine),
]);