[Poppler-bugs] [Bug 97506] New: GooString wastes 4 bytes on 64-bit systems

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97506

            Bug ID: 97506
           Summary: GooString wastes 4 bytes on 64-bit systems
           Product: poppler
           Version: unspecified
          Hardware: Other
                OS: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: general
          Assignee: poppler-bugs at lists.freedesktop.org
          Reporter: jakubkucharski97 at gmail.com

GooString has 3 fields:
char sStatic[STR_STATIC_SIZE];
int length;
char *s;

32-bit system without the patches:
STR_STATIC_SIZE:      24
sizeof(MemoryLayout): 12
sizeof(char*):         4
sizeof(int):           4
sizeof(GooString):    32
------------------------
Used = STR_STATIC_SIZE + sizeof(int) + sizeof(char*) = 24 + 4 + 4 = 32 out of
32 taken (100% efficiency)

64-bit system without the patches:
STR_STATIC_SIZE:      16
sizeof(MemoryLayout): 24
sizeof(char*):         8
sizeof(int):           4
sizeof(GooString):    32
------------------------
Used = STR_STATIC_SIZE + sizeof(int) + sizeof(char*) = 16 + 4 + 8 = 28 out of
32 taken (87.5% efficiency)

Right now STR_STATIC_SIZE is calculated using class MemoryLayout which doesn't
help, but only makes it harder due to memory alignment performed by the
compiler (sizeof(MemoryLayout) on a 64-bit system >= the sum of MemoryLayout's
fields sizes).

With my patches sizeof(GooString) is still == 32, and there are no wasted
bytes.

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