Re: [Libguestfs] [PATCH nbdkit 1/9] common: Add a generic implementation of vectors.

Can be used for building up lists of things, especially lists of strings. --- common/include/Makefile.am | 6 +++ common/include/test-vector.c | 90 +++++++++++++++++++++++++++++++++ common/include/vector.h | 96 ++++++++++++++++++++++++++++++++++++ .gitignore | 1 + 4 files changed, 193 insertions(+)

+++ b/common/include/vector.h

+/* Simple implementation of appendable vector. There are two main + * use-cases we consider: lists of strings (either with a defined + * length, or NULL-terminated), and lists of numbers. It is generic + * so could be used for lists of anything (eg. structs) where being + * able to append easily is important. + */ + +#ifndef NBDKIT_VECTOR_H +#define NBDKIT_VECTOR_H + +#include <assert.h> + +#define DEFINE_VECTOR_TYPE(name, type) \ + struct name { \ + type *ptr; /* Pointer to array of items. */ \ + size_t size; /* Number of valid items in the array. */ \ + size_t alloc; /* Number of items allocated. */ \ + }; \ + typedef struct name name; \ + static inline int \ + name##_extend (name *v, size_t n) \ + { \ + return generic_vector_extend ((struct generic_vector *)v, n, \ + sizeof (type)); \ + } \ + static inline int \ + name##_append (name *v, type elem) \ + { \ + if (v->size >= v->alloc) { \ + if (name##_extend (v, 1) == -1) return -1; \ + } \ + v->ptr[v->size++] = elem; \ + return 0; \ + } \ + static inline void \ + name##_iter (name *v, void (*f) (type elem)) \

+ { \ + size_t i; \ + for (i = 0; i < v->size; ++i) \ + f (v->ptr[i]); \ + }

+ +#define empty_vector { .ptr = NULL, .size = 0, .alloc = 0 }

+ +struct generic_vector { + void *ptr; + size_t size; + size_t alloc; +}; + +static int +generic_vector_extend (struct generic_vector *v, size_t n, size_t itemsize) +{ + void *newptr; + + newptr = realloc (v->ptr, (n + v->alloc) * itemsize); + if (newptr == NULL) + return -1; + v->ptr = newptr; + v->alloc += n; + return 0; +}