objectsize

C++ object size with virtual methods

由 不打扰是莪最后的温柔 提交于 2019-12-17 04:31:07
问题 I have some questions about the object size with virtual. 1) virtual function class A { public: int a; virtual void v(); } The size of class A is 8bytes....one integer(4 bytes) plus one virtual pointer(4 bytes) It's clear! class B: public A{ public: int b; virtual void w(); } What's the size of class B? I tested using sizeof B, it prints 12 Does it mean that only one vptr is there even both of class B and class A have virtual function? Why there is only one vptr? class A { public: int a;

C++ object size with virtual methods

由 心不动则不痛 提交于 2019-12-17 04:30:11
问题 I have some questions about the object size with virtual. 1) virtual function class A { public: int a; virtual void v(); } The size of class A is 8bytes....one integer(4 bytes) plus one virtual pointer(4 bytes) It's clear! class B: public A{ public: int b; virtual void w(); } What's the size of class B? I tested using sizeof B, it prints 12 Does it mean that only one vptr is there even both of class B and class A have virtual function? Why there is only one vptr? class A { public: int a;

C++ object size with virtual methods

由 北战南征 提交于 2019-12-17 04:30:02
问题 I have some questions about the object size with virtual. 1) virtual function class A { public: int a; virtual void v(); } The size of class A is 8bytes....one integer(4 bytes) plus one virtual pointer(4 bytes) It's clear! class B: public A{ public: int b; virtual void w(); } What's the size of class B? I tested using sizeof B, it prints 12 Does it mean that only one vptr is there even both of class B and class A have virtual function? Why there is only one vptr? class A { public: int a;

Is there a way to guess the size of data.frame based on rows, columns and variable types?

由 ぃ、小莉子 提交于 2019-12-06 02:59:30
问题 I am expecting to generate a lot of data and then catch it R. How can I estimate the size of the data.frame (and thus memory needed) by the number of rows, number of columns and variable types? Example. If I have 10000 rows and 150 columns out of which 120 are numeric, 20 are strings and 10 are factor level, what is the size of the data frame I can expect? Will the results change depending on the data stored in the columns (as in max(nchar(column)) )? > m <- matrix(1,nrow=1e5,ncol=150) > m <-

Is there a way to guess the size of data.frame based on rows, columns and variable types?

由 只谈情不闲聊 提交于 2019-12-04 09:01:05
I am expecting to generate a lot of data and then catch it R. How can I estimate the size of the data.frame (and thus memory needed) by the number of rows, number of columns and variable types? Example. If I have 10000 rows and 150 columns out of which 120 are numeric, 20 are strings and 10 are factor level, what is the size of the data frame I can expect? Will the results change depending on the data stored in the columns (as in max(nchar(column)) )? > m <- matrix(1,nrow=1e5,ncol=150) > m <- as.data.frame(m) > object.size(m) 120009920 bytes > a=object.size(m)/(nrow(m)*ncol(m)) > a 8

Mongo = get size of single document

由 半城伤御伤魂 提交于 2019-11-27 06:31:52
I encountered a strange behavior of mongo and I would like to clarify it a bit... My request is simple as that: I would like to get a size of single document in collection. I found two possible solutions: Object.bsonsize - some javascript method that should return a size in bytes db.collection.stats() - where there is a line 'avgObjSize' that produce some "aggregated"(average) size view on the data. It simply represents average size of single document. When I create test collection with only one document, both functions returns different values. How is it possible? Does it exist some other

Size of Huge Objects directly allocated to Old Generation

由 谁说我不能喝 提交于 2019-11-26 21:59:35
Recently I've been reading about object allocations in different generations in Java. Most of the times new objects are allocated in Eden (part of Young Generation) and then they're promoted to Old Generation if any of the following criteria are met. (1) Object's age reached the tenuring threshold (2) Survivor space (to) is full when objects are being copied from Eden (or) another survivor space(from) But there's also a special case in which objects are directly allocated in the Old Generation instead of being promoted from the young generation. This happens when the object that we're trying

Mongo = get size of single document

由 |▌冷眼眸甩不掉的悲伤 提交于 2019-11-26 10:24:39
问题 I encountered a strange behavior of mongo and I would like to clarify it a bit... My request is simple as that: I would like to get a size of single document in collection. I found two possible solutions: Object.bsonsize - some javascript method that should return a size in bytes db.collection.stats() - where there is a line \'avgObjSize\' that produce some \"aggregated\"(average) size view on the data. It simply represents average size of single document. When I create test collection with

Size of Huge Objects directly allocated to Old Generation

由 元气小坏坏 提交于 2019-11-26 08:07:26
问题 Recently I\'ve been reading about object allocations in different generations in Java. Most of the times new objects are allocated in Eden (part of Young Generation) and then they\'re promoted to Old Generation if any of the following criteria are met. (1) Object\'s age reached the tenuring threshold (2) Survivor space (to) is full when objects are being copied from Eden (or) another survivor space(from) But there\'s also a special case in which objects are directly allocated in the Old
订阅 objectsize