HBASE-21879 Read HFile ’s Block into ByteBuffer directly. 1. Background For reducing the Java GC impact to p99/p999 RPC latency, HBase 2.x has made an offheap read and write path. The KV are allocated BucketCache firstly, if the Cache misses, go to the HFile and read the corresponding block. The workflow: reading block from cache OR sending cells to client, is basically not involved in heap memory allocations that the process of reading the Block from HFile is still copied to the heap firstly, the heap block won’t free unless the WriterThread of BucketCache flushes the Block to offheap IOEngine successfully

used in combina- tion with modules.) Synopsis • Declarations can be marked as abstract using the block keyword abstract. • Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where-blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. 5 Agda Documentation Remember that the abstract definition of does not unfold in type signatures, even when in an abstract block! However, if we make shape-of- private, unfolding of abstract definitions like is enabled, and we

are used in combination with modules.) Synopsis Declarations can be marked as abstract using the block keyword abstract. Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where- blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. Examples Integers Remember that the abstract definition of ℤ does not unfold in type signatures, even when in an abstract block! However, if we make shape-of-ℤ private, unfolding of abstract definitions like ℤ is enabled, and

are used in combination with modules.) Synopsis Declarations can be marked as abstract using the block keyword abstract. Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where- blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. Examples Integers Remember that the abstract definition of ℤ does not unfold in type signatures, even when in an abstract block! However, if we make shape-of-ℤ private, unfolding of abstract definitions like ℤ is enabled, and

combina- tion with modules.) 3.1.1 Synopsis • Declarations can be marked as abstract using the block keyword abstract. • Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where-blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. 9 Agda User Manual Remember that the abstract definition of does not unfold in type signatures, even when in an abstract block! However, if we make shape-of- private, unfolding of abstract definitions like is enabled, and we

combina- tion with modules.) 3.1.1 Synopsis • Declarations can be marked as abstract using the block keyword abstract. • Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where-blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. 9 Agda User Manual Remember that the abstract definition of does not unfold in type signatures, even when in an abstract block! However, if we make shape-of- private, unfolding of abstract definitions like is enabled, and we

are used in combination with modules.) Synopsis Declarations can be marked as abstract using the block keyword abstract. Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where- blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. Examples Integers Remember that the abstract definition of ℤ does not unfold in type signatures, even when in an abstract block! However, if we make shape-of-ℤ private, unfolding of abstract definitions like ℤ is enabled, and

combina- tion with modules.) 3.1.1 Synopsis • Declarations can be marked as abstract using the block keyword abstract. • Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where-blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. 9 Agda User Manual Remember that the abstract definition of does not unfold in type signatures, even when in an abstract block! However, if we make shape-of- private, unfolding of abstract definitions like is enabled, and we

are used in combination with modules.) Synopsis Declarations can be marked as abstract using the block keyword abstract. Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where- blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. Examples Integers Remember that the abstract definition of ℤ does not unfold in type signatures, even when in an abstract block! However, if we make shape-of-ℤ private, unfolding of abstract definitions like ℤ is enabled, and

are used in combination with modules.) Synopsis Declarations can be marked as abstract using the block keyword abstract. Outside of abstract blocks, abstract definitions do not reduce, they are treated abstract keyword block extends recursively to the where- blocks of a function and the declarations inside of a record declaration, but not inside modules declared in an abstract block. Examples Integers Remember that the abstract definition of ℤ does not unfold in type signatures, even when in an abstract block! However, if we make shape-of-ℤ private, unfolding of abstract definitions like ℤ is enabled, and