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fb40a72b45
re: Issue https://github.com/Unidata/netcdf-c/issues/2685 re: PR https://github.com/Unidata/netcdf-c/pull/2179 As noted in PR https://github.com/Unidata/netcdf-c/pull/2179, the old code did not allow for reclaiming instances of types, nor for properly copying them. That PR provided new functions capable of reclaiming/copying instances of arbitrary types. However, as noted by Issue https://github.com/Unidata/netcdf-c/issues/2685, using these most general functions resulted in a significant performance degradation, even for common cases. This PR attempts to mitigate the cost of using the general reclaim/copy functions in two ways. First, the previous functions operating at the top level by using ncid and typeid arguments. These functions were augmented with equivalent versions that used the netcdf-c library internal data structures to allow direct access to needed information. These new functions are used internally to the library. The second mitigation involves optimizing the internal functions by providing early tests for common cases. This avoids unnecessary recursive function calls. The overall result is a significant improvement in speed by a factor of roughly twenty -- your mileage may vary. These optimized functions are still not as fast as the original (more limited) functions, but they are getting close. Additional optimizations are possible. But the cost is a significant "uglification" of the code that I deemed a step too far, at least for now. ## Misc. Changes 1. Added a test case to check the proper reclamation/copy of complex types. 2. Found and fixed some places where nc_reclaim/copy should have been used. 3. Replaced, in the netcdf-c library, (almost all) occurrences of nc_reclaim_copy with calls to NC_reclaim/copy. This plus the optimizations is the primary speed-up mechanism. 4. In DAP4, the metadata is held in a substrate in-memory file; this required some changes so that the reclaim/copy code accessed that substrate dispatcher rather than the DAP4 dispatcher. 5. Re-factored and isolated the code that computes if a type is (transitively) variable-sized or not. 6. Clean up the reclamation code in ncgen; adding the use of nc_reclaim exposed some memory problems.
63 lines
2.5 KiB
C
63 lines
2.5 KiB
C
/*********************************************************************
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* Copyright 2018, UCAR/Unidata
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* See netcdf/COPYRIGHT file for copying and redistribution conditions.
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*********************************************************************/
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#ifndef GENERATE_H
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#define GENERATE_H 1
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typedef struct Generator Generator;
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void alignbuffer(struct NCConstant* prim, Bytebuffer* buf);
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/* Code dump support procedures */
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void bbindent(Bytebuffer*,const int);
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void bbprintf(Bytebuffer*,const char *fmt, ...); /* append */
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void bbprintf0(Bytebuffer*,const char *fmt, ...); /* clear, then append*/
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/* Following dump to codebuffer */
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void codeprintf(const char *fmt, ...);
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void codedump(Bytebuffer*);
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void codepartial(const char*);
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void codeline(const char*);
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void codelined(int n,const char*);
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void codeflush(void); /* flush codebuffer to stdout */
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void commify(Bytebuffer* buf);
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char* word(char* p, Bytebuffer* buf);
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/* Provide buffers for language based generators */
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extern Bytebuffer* codebuffer; /* buffer over the std output */
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extern Bytebuffer* stmt; /* single stmt text generation */
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/* From genchar.c */
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void gen_charattr(Datalist*, Bytebuffer*);
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void gen_charseq(Datalist*, Bytebuffer*);
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void gen_chararray(Dimset*, int, Datalist*, Bytebuffer*, Datalist*);
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typedef enum ListClass {
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LISTDATA, LISTATTR, LISTVLEN, LISTCOMPOUND, LISTFIELDARRAY
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} ListClass;
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struct Generator {
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void* globalstate; /* per-generator; per list state is in the method args where needed */
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int (*charconstant)(Generator*,struct Symbol*,Bytebuffer*,...);
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int (*constant)(Generator*,struct Symbol*,NCConstant*,Bytebuffer*,...);
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int (*listbegin)(Generator*,struct Symbol*,void*,ListClass,size_t,Bytebuffer*,int*,...);
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int (*list)(Generator*,struct Symbol*,void*,ListClass,int,size_t,Bytebuffer*,...);
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int (*listend)(Generator*,struct Symbol*,void*,ListClass,int,size_t,Bytebuffer*,...);
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int (*vlendecl)(Generator*,struct Symbol*,Bytebuffer*,int,size_t,...);
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int (*vlenstring)(Generator*,struct Symbol*,Bytebuffer*,int*,size_t*,...);
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};
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extern int generator_getstate(Generator*,void**);
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extern int generator_reset(Generator*,void*);
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typedef int (*Writer)(Generator*,struct Symbol*,Bytebuffer*,int,const size_t*,const size_t*);
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extern void generate_attrdata(struct Symbol*, Generator*, Writer writer, Bytebuffer*);
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extern void generate_vardata(struct Symbol*, Generator*, Writer writer, Bytebuffer*);
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extern void generate_basetype(struct Symbol*,NCConstant*,Bytebuffer*,Datalist*,Generator*);
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#endif /*DATA_H*/
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