vrb_init_opt(3)

🌸 NAME 🌸

vrb_init_opt — initialize a virtual ring buffer. This vrb_init_opt(3) page comes from the VRB Programmer's Manual, bestie, and it's lowkey iconic: it sets up your virtual ring buffer. 💖

📚 LIBRARY 📚

• -lvrb — that's the library. Link it and you're in.

✨ SYNOPSIS ✨

#include <vrb.h>

vrb_p vrb_init_opt(vrb_p vrb, size_t size, const char *name, int
options);

🦋 DESCRIPTION 🦋

vrb_init_opt initializes a static or pre-allocated virtual ring buffer structure. Periodt. That's the main character job. 👑

A virtual ring buffer is a character FIFO queue with a special property: the way that any sequence of characters in the buffer may be accessed as a single contiguous block of memory, eliminating the need to split any sequence to handle a buffer wraparound. It's giving seamless, no awkward seam at the end. 😭✨

🎀 ARGUMENTS 🎀

• vrb_p vrb — specifies the virtual ring buffer structure to be initialized. The caller must release buffer resources via vrb_uninit(3) when this virtual ring buffer is no longer needed. If NULL is given, a new virtual ring buffer structure is allocated, and the caller must release buffer resources via vrb_destroy(3) when an allocated virtual ring buffer is no longer needed. iykyk.
• size_t size — specifies the requested minimum buffer size to be allocated. The given value will be rounded up to the nearest or equal whole multiple of the system page size. The virtual ring buffer is implemented by mapping two adjacent blocks of memory to the same memory object. Thus, twice as much virtual address space will be used and the specified size must be less than half of the available virtual address space for this process. math is math, bestie 🧮.
• const char *name — specifies an optional temporary name pattern or an actual name of a file to be used as backing store via mmap(2) in a mounted filesystem in which the process has write permission. If the name string ends in "XXXXXX" then mkstemp(3) will be used to make the file unique. Otherwise it will be used as is. If the named file already exists or otherwise cannot be opened for write, an error will occur. If NULL is given, swap space will be used as backing store via shmat(2). name vibes: choose carefully 🫶.
• int options — specifies option flags that may be given to alter the behaviour of the virtual ring buffer. The implemented options are:
  • VRB_NOGUARD — Do not include guard pages that would protect against buffer overflow errors. lowkey risky, but okay 💀.
  • VRB_ENVGUARD — Override VRB_NOGUARD if the environment variable VRBGUARD is defined with a value other than the string "0". env var said what it said 🌿.

💅 RETURN VALUE 💅

The return type is vrb_p. On success, a handle (pointer) to the newly created virtual ring buffer is returned. On error, NULL is returned. iconic when it works, sad when it doesn't 😭.

🚨 ERRORS 🚨

If an error is returned, then errno will have one of the following values:

• EINVAL — A buffer size was requested which is too large for address space allocation arithmetic. too much math, too much address space.
• ENOMEM — Out of memory allocating the virtual ring buffer structure. the memory said no.
• - — An errno value set by a failing system call. system call said nope.

🌈 SEE ALSO 🌈

Go be nosy, bestie: vrb(3), vrb_capacity(3), vrb_data_len(3), vrb_data_ptr(3), vrb_destroy(3), vrb_get(3), vrb_get_min(3), vrb_give(3), vrb_init(3), vrb_is_empty(3), vrb_is_full(3), vrb_is_not_empty(3), vrb_is_not_full(3), vrb_move(3), vrb_new(3), vrb_new_opt(3), vrb_put(3), vrb_put_all(3), vrb_read(3), vrb_read_min(3), vrb_resize(3), vrb_space_len(3), vrb_space_ptr(3), vrb_take(3), vrb_uninit(3), vrb_write(3), vrb_write_min(3). obsessed

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xoxo, your Unix bestie 💅 — this one is from vrb, dated 2002-09-30, and it's filed under vrb_init_opt(3). Slay responsibly. 🫶