feat: libfmt prototype added from plan9

1 files changed, 60 insertions, 0 deletions

diff --git a/sys/libfmt/buffer.c b/sys/libfmt/buffer.c
new file mode 100644
index 0000000..0099e72
--- /dev/null
+++ b/sys/libfmt/buffer.c
@@ -0,0 +1,60 @@
+#include "internal.h"
+
+static int
+flush(fmt·State *io)
+{
+    int  n;
+    char *s;
+
+    void *heap = io->heap;
+    mem·Reallocator mem = io->mem;
+
+    if(!io->buffer.beg)
+        return 0;
+
+    n = 2*(uintptr)io->file;
+    s = io->buffer.beg;
+
+    io->buffer.beg = mem.realloc(heap, io->buffer.beg, n, 1);
+    if(!io->buffer.beg){
+        io->file = io->buffer.cur = io->buffer.end = nil;
+        mem.free(heap, s);
+        return 0;
+    }
+    io->file = (void*)(uintptr)n;
+    io->buffer.cur = io->buffer.beg + (io->buffer.cur - s);
+    io->buffer.end = io->buffer.beg + n - 1;
+
+    return 1;
+}
+
+int
+fmt·make(mem·Reallocator mem, void *heap, fmt·State *io)
+{
+    int n;
+
+    memset(io, 0, sizeof(*io));
+
+    n = 32;
+    io->buffer.beg = io->buffer.cur = mem.alloc(heap, n, 1);
+    if(!io->buffer.beg)
+        return -1;
+    io->buffer.end = io->buffer.beg + n - 1;
+
+    io->flush = flush;
+    io->file  = (void*)(uintptr)n;
+    io->n     = 0;
+
+    fmt·setlocale(io, nil, nil, nil);
+    return 0;
+}
+
+void
+fmt·free(fmt·State *io)
+{
+    void *heap = io->heap;
+    mem·Reallocator mem = io->mem;
+
+    mem.free(heap, io->buffer.beg);
+    io->buffer.beg = io->buffer.cur = io->buffer.end = nil;
+}