Make various preparations for upcoming features

A lot of this is random WIP from a while back, at least a month ago, and
is being committed now to get it out of the way so that other patches
can be brought in and integrated against it without causing headaches.

Also rolled into this commit is a way to distinguish plugin_unload from
exiting the game. This is required for another soon-to-be-integrated
feature to avoid crashing on exit, and could in theory also be used to
speed up unloading on exit in future. While we're at it, this also
avoids the need to linearly scan through the plugin list to do the
old branch unloading fix, because we can.

Rough summary of the other smaller stuff I can remember doing:
- Rework bitbuf a bit
- Add some cryptographic nonsense in ac.c (not final at all)
- Introduce the first couple of "chunklets" libraries as a sort-of
  subproject of this one
- Tidy up random small bits and bobs
- Add source for a small keypair generation tool
- Rework democustom to be very marginally more useful

1 files changed, 350 insertions, 0 deletions

diff --git a/src/chunklets/msg.h b/src/chunklets/msg.h
new file mode 100644
index 0000000..b85bde3
--- /dev/null
+++ b/src/chunklets/msg.h
@@ -0,0 +1,350 @@
+/*
+ * Copyright © 2023 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef INC_CHUNKLETS_MSG_H
+#define INC_CHUNKLETS_MSG_H
+
+#ifdef __cplusplus
+#define _msg_Bool bool
+extern "C" {
+#else
+#define _msg_Bool _Bool
+#endif
+
+/*
+ * Writes a nil (null) message to the buffer out. Always writes a single byte.
+ *
+ * out must point to at least 1 byte.
+ */
+void msg_putnil(unsigned char *out);
+
+/*
+ * Writes the boolean val to the buffer out. Always writes a single byte.
+ *
+ * out must point to at least 1 byte.
+ */
+void msg_putbool(unsigned char *out, _msg_Bool val);
+
+/*
+ * Writes the integer val in the range [-32, 127] to the buffer out. Values
+ * outside this range will produce an undefined encoding. Always writes a single
+ * byte.
+ *
+ * out must point to at least 1 byte.
+ *
+ * It is recommended to use msg_puts() for arbitrary signed values or msg_putu()
+ * for arbitrary unsigned values. Those functions will produce the smallest
+ * possible encoding for any value.
+ */
+void msg_puti7(unsigned char *out, signed char val);
+
+/*
+ * Writes the signed int val in the range [-128, 127] to the buffer out.
+ *
+ * out must point to at least 2 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2}.
+ *
+ * It is recommended to use msg_puts() for arbitrary signed values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_puts8(unsigned char *out, signed char val);
+
+/*
+ * Writes the unsigned int val in the range [0, 255] to the buffer out.
+ *
+ * out must point to at least 2 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2}.
+ *
+ * It is recommended to use msg_putu() for arbitrary unsigned values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_putu8(unsigned char *out, unsigned char val);
+
+/*
+ * Writes the signed int val in the range [-65536, 65535] to the buffer out.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3}.
+ *
+ * It is recommended to use msg_puts() for arbitrary signed values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_puts16(unsigned char *out, short val);
+
+/*
+ * Writes the unsigned int val in the range [0, 65536] to the buffer out.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3}.
+ *
+ * It is recommended to use msg_putu() for arbitrary unsigned values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_putu16(unsigned char *out, unsigned short val);
+
+/*
+ * Writes the signed int val in the range [-2147483648, 2147483647] to the
+ * buffer out.
+ *
+ * out must point to at least 5 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3, 5}.
+ *
+ * It is recommended to use msg_puts() for arbitrary signed values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_puts32(unsigned char *out, int val);
+
+/*
+ * Writes the unsigned int val in the range [0, 4294967295] to the buffer out.
+ *
+ * out must point to at least 5 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3, 5}.
+ *
+ * It is recommended to use msg_putu() for arbitrary unsigned values. That
+ * function will produce the smallest possible encoding for any value.
+ */
+int msg_putu32(unsigned char *out, unsigned int val);
+
+/*
+ * Writes the signed int val in the range [-9223372036854775808,
+ * 9223372036854775807] to the buffer out.
+ *
+ * out must point to at least 9 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3, 5, 9}.
+ */
+int msg_puts(unsigned char *out, long long val);
+
+/*
+ * Writes the unsigned int val in the range [0, 18446744073709551616] to the
+ * buffer out.
+ *
+ * out must point to at least 9 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3, 5, 9}.
+ */
+int msg_putu(unsigned char *out, unsigned long long val);
+
+/*
+ * Writes the IEEE 754 single-precision float val to the buffer out. Always
+ * writes 5 bytes.
+ *
+ * out must point to at least 5 bytes.
+ */
+void msg_putf(unsigned char *out, float val);
+
+/*
+ * Writes the IEEE 754 double-precision float val to the buffer out.
+ *
+ * out must point to at least 9 bytes.
+ *
+ * Returns the number of bytes written, one of {5, 9}.
+ */
+int msg_putd(unsigned char *out, double val);
+
+/*
+ * Writes the string size sz in the range [0, 15] to the buffer out. Values
+ * outside this range will produce an undefined encoding. Always writes a single
+ * byte.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * bytes of the actual string, which must be valid UTF-8.
+ *
+ * out must point to at least 1 byte.
+ *
+ * It is recommended to use msg_putssz() for arbitrary string sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+void msg_putssz5(unsigned char *out, int sz);
+
+/*
+ * Writes the string size sz in the range [0, 255] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * bytes of the actual string, which must be valid UTF-8.
+ *
+ * out must point to at least 2 bytes.
+ *
+ * It is recommended to use msg_putssz() for arbitrary string sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+int msg_putssz8(unsigned char *out, int sz);
+
+/*
+ * Writes the string size sz in the range [0, 65535] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * bytes of the actual string, which must be valid UTF-8.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * It is recommended to use msg_putssz() for arbitrary string sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+int msg_putssz16(unsigned char *out, int sz);
+
+/*
+ * Writes the string size sz in the range [0, 4294967295] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * bytes of the actual string, which must be valid UTF-8.
+ *
+ * out must point to at least 5 bytes.
+ */
+int msg_putssz(unsigned char *out, unsigned int sz);
+
+/*
+ * Writes the binary blob size sz in the range [0, 255] to the buffer out.
+ * Always writes 2 bytes.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N bytes of the actual data.
+ *
+ * out must point to at least 2 bytes.
+ *
+ * It is recommended to use msg_putbsz() for arbitrary binary blob sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+void msg_putbsz8(unsigned char *out, int sz);
+
+/*
+ * Writes the binary blob size sz in the range [0, 65535] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N bytes of the actual data.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3}.
+ *
+ * It is recommended to use msg_putbsz() for arbitrary binary blob sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+int msg_putbsz16(unsigned char *out, int sz);
+
+/*
+ * Writes the binary blob size sz in the range [0, 4294967295] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N bytes of the actual data.
+ *
+ * out must point to at least 5 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 2, 3, 5}.
+ */
+int msg_putbsz(unsigned char *out, unsigned int sz);
+
+/*
+ * Writes the array size sz in the range [0, 15] to the buffer out. Values
+ * outside this range will produce an undefined encoding. Always writes a single
+ * byte.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * other messages, which form the contents of the array.
+ *
+ * out must point to at least 1 byte.
+ *
+ * It is recommended to use msg_putasz() for arbitrary array sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+void msg_putasz4(unsigned char *out, int sz);
+
+/*
+ * Writes the array size sz in the range [0, 65535] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * other messages, which form the contents of the array.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 3}.
+ *
+ * It is recommended to use msg_putasz() for arbitrary array sizes. That
+ * function will produce the smallest possible encoding for any size value.
+ */
+int msg_putasz16(unsigned char *out, int sz);
+
+/*
+ * Writes the array size sz in the range [0, 4294967295] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by N
+ * other messages, which form the contents of the array.
+ *
+ * out must point to at least 5 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 3, 5}.
+ */
+int msg_putasz(unsigned char *out, unsigned int sz);
+
+/*
+ * Writes the map size sz in the range [0, 15] to the buffer out. Values
+ * outside this range will produce an undefined encoding. Always writes a single
+ * byte.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N * 2 other messages, which form the contents of the map as keys followed by
+ * values in alternation.
+ *
+ * out must point to at least 1 byte.
+ *
+ * It is recommended to use msg_putmsz() for arbitrary map sizes. That function
+ * will produce the smallest possible encoding for any size value.
+ */
+void msg_putmsz4(unsigned char *out, int sz);
+
+/*
+ * Writes the array size sz in the range [0, 65536] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N * 2 other messages, which form the contents of the map as keys followed by
+ * values in alternation.
+ *
+ * out must point to at least 3 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 3}.
+ *
+ * It is recommended to use msg_putmsz() for arbitrary map sizes. That function
+ * will produce the smallest possible encoding for any size value.
+ */
+int msg_putmsz16(unsigned char *out, int sz);
+
+/*
+ * Writes the array size sz in the range [0, 4294967295] to the buffer out.
+ *
+ * In a complete message stream, a size of N must be immediately followed by
+ * N * 2 other messages, which form the contents of the map as keys followed by
+ * values in alternation.
+ *
+ * out must point to at least 5 bytes.
+ *
+ * Returns the number of bytes written, one of {1, 3, 5}.
+ */
+int msg_putmsz(unsigned char *out, unsigned int sz);
+
+#ifdef __cplusplus
+}
+#endif
+#undef _msg_Bool
+
+#endif
+
+// vi: sw=4 ts=4 noet tw=80 cc=80