Change A1: Tell ByteArrayOutputStream required capacity #8
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The byte array in `ByteArrayOutputStream` doubles in size every time capacity is exhausted - for an object just over 1GB in size, the buffer will eventually grow to 2GB in size - unnecessarily large, and involving a lot of array copies (`ceil(log_2 (N/32))` copies). https://github.com/openjdk/jdk/blob/218829e0a2a3ae5599b81733df53557966392033/src/java.base/share/classes/java/io/ByteArrayOutputStream.java#L100-L101 If we just tell the Content Length to initialise the `ByteArrayOutputStream` with a byte array of the right size, the array will never get bigger than it needs to be - and it won't have do array-resizing either.
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The byte array in
ByteArrayOutputStreamdoubles in size every time capacity is exhausted - for an object just over 1GB in size, the buffer will eventually grow to 2GB in size - unnecessarily large, and involving a lot of array copies (ceil(log_2 (N/32))copies).https://github.com/openjdk/jdk/blob/218829e0a2a3ae5599b81733df53557966392033/src/java.base/share/classes/java/io/ByteArrayOutputStream.java#L100-L101
If we just tell the Content Length to initialise the
ByteArrayOutputStreamwith a byte array of the right size, the array will never get bigger than it needs to be - and it won't have do array-resizing either.Required RAM: 934 MB