Add ARCHITECTURE.md.

ARCHITECTURE.md

@@ -0,0 +1,149 @@
+# Base.
+
+### `PCH`
+
+Brings in all the external and standard headers. <br/>
+Apart from c++std stuff we have:
+- `mruby` and almost all it's subheaders.
+- `pcre2` (For regex.)
+- `grapheme.h` - The suckless libgrapheme (to find utf8 boundaries)
+- `unicode_width.h` - To find terminal width of unicode char's.
+
+*Maybe try removing some of them ive probably stopped using.*
+
+### `definitions.h`
+
+- Defines the `bed` namespace
+- Forward declaration of `BEd` type needed by all.
+- `fatal_error` definition, a msg, code (quits application on being thrown)
+- `ed_error`. just a message (stops the current cycle of the ed repl.)
+
+### `bed.h`
+
+**As this is based heavily on the internals, and so ill look into it at the end.**
+
+# `Internal`
+
+## `Vase`
+
+- This module doesn't depend on any other.
+- It's namespace is `bed::internal::vase`
+- Vase is the module to do with the actual storage and handling of a disk backed immutable and reference counted avl piece tree.
+- It is a O(log n) per edit text datatype.
+
+### `constants.h`
+
+Defines `PETAL_SIZE_MAX` as `32 * 1024`.
+- `PETAL_SIZE_MAX` limits teh size of a petal which makes multiple O(n) in petal searches O(1) as it is now bounded.
+
+### `storage/`
+
+A storage is something that stores the actual text, the text is actually stored in storages which are referenced by the trees.
+
+#### `storage.h`
+
+Defines the virtual `Storage` class.
+It has the methods:
+- `const char *read(uint64_t pos)`: reads text from position `pos` and returns a pointer to it.
+- `uint64_t length()`: returns the length of the storage.
+- `void retain() / release()`: Methods to help with refcounted storages.
+
+#### `original.h`
+
+Defines the `Original` type of storage.
+This is a refcounted storage.
+
+It has the fields:
+- `atomic_uint64_t refs{0}`: refcount
+- `const char *buf`: pointer to the actual text.
+- `uint64_t len`
+- `int fd = -1`: the file descriptor of teh undelying disk storage.
+
+It adds the method `initialize` over the base class.
+
+`src/vase/storage/original.cc`.
+
+The constructor uses `mkstemp` to make a temp file, then unlinks it to hide it from the fs but keeps the fd alive.
+
+`initialize` then `mmap`s the fd into a non modifyable pointer managed by the kernel then closes the fd itself.
+- This is what gives us a pointer to the file contents that the kernel can load and evict from memory as needed, and therefore if we have say a 500MB file loaded, but the cursor is arount 200MB and the user is only editing a couple lines around that, the rest of the file will not be using your memory, it might be loaded but if needed the kernel can evict it.
+
+The call site fills the fd before calling initialze, it cannot be modified after that.
+
+#### `append.h`
+
+Defines the `Append` type of storage.
+This is not actually refcounted, it is to be owned by the application just once and reused all throughout.
+It contains the actively typed stuff.
+
+It has the fields:
+- `const char *buf`: pointer to the actual text.
+- `uint64_t allocated_capacity`: the amount of bytees that can be written to it without needing to increase the size.
+- `uint64_t current_size`: Stores the size of actual text stored in it. (the cursor)
+- `int fd = -1`: the file descriptor of the underlying disk storage.
+
+It has the methods `append` (with 2 overloads) and private `grow` over the base class.
+`retain` and `release` do nothing.
+
+`src/vase/storage/append.cc`.
+
+The constructor uses `mkstemp` an `unlink` similar to the original storage.
+It then `ftruncate`s the file to `2^30` bytes or 1GiB this makes writing 1gb to the file possible but does'nt neccasarily use up 1gb on the disk.
+But when `mmap`ing we set `PROT_READ | PROT_WRITE` and `MAP_SHARED` to be able to write edits to disk.
+
+`grow` works by doubling the capacity `ftruncat`ing the fd to the new capacity and then on `linux` it uses `mremap` to remap to the new file size, but otherwise we `munmap` and `mmap` into the new size.
+
+The append methods append text into the buffer (either a single char or char * + len), they may grow the storage size. (the char*+len version uses memcpy).
+
+### `shard.h`
+
+Defines the actual peice tree.
+
+The tree is a polymorhic set of classes.
+
+The base class `Shard` has:
+- `enum Kind : uint8_t kind`: Branch or Petal.
+- `uint16_t height`: the tree height (for avl balancing.)
+- `atomic_uint32_t refs`: the refcount.
+- `uint64_t length`: the length in bytes of this (sub)tree.
+- `uint64_t lines`: the number of `\n` in this subtree.
+- It starts refcount at 1.
+
+The `Branch` class adds:
+- `Shard *left/right` the subtrees.
+- its constructor takes l, r and sets length/lines `(l->length + r->length)`
+- and height `1 + std::max(l->height, r->height)`
+
+The `Petal` (leaf) class adds:
+- `Storage *` a pointer to the storage used.
+- `uint64_t pos` the position in the storage its text starts at.
+- it takes `(uint64_t length, uint64_t lines, Storage *source, uint64_t pos)`
+- it retains `source`. (usefull for refcounted sotrages.)
+
+A `nullptr` `Shard*` is an empty peice of text (i.e. valid).
+
+`src/internal/vase/shard.cc`: defines a set of static function on the Shard class. (All the applications of it.)
+
+the operations methods are:
+- `retain/release` retain/releases them, if freeing a leaf it also releases the storage and for branches it releases both subtrees. nullptr's are ignored.
+- `balance/rotate_(right/left) and height/balance factor` are for doing simple avl balancing operations.
+- `concat` borrows 2 pointers to `Shard` and returns an owned Shard*.
+- `split` borrows a `Shard` and returns a `pair<Shard*, Shard*>` of 2 owned shards.
+- `merge_leaves` works similar to concat but it tries to merge the middle bit if they have their physical representation in order. for example if i have a shard `hell` and i type the letter `o` and because i'd been typing in order the Append storage will have text `hello` we can merge them into a single petal.
+- `append` similar to concat, but uses merge_leaves, useful for small appends like when typing.
+- `build` takes a pointer to an array of `Shard*` and start and end then makes a single avl balanced `Shard*` out of it it is generally faster than calling concat on each peice when we have many.
+
+Then for building a Shard* in the first place we have:
+- `from_command(const char *cmd)` runs the \0 terminated command string and reads its STDOUT and returns an owned Shard*.
+- `from_file(const std::filesystem::path &path)` reads the file at path.
+- `from_string(const char *data, uint64_t len)` loads the string given into a new storage, (normally inserting text can work by inserting into the append storage but this function loads it into a `OriginalStorage` object.).
+These methods all clip the final newline if it exists.
+And they also create a new `OriginalStorage` object.
+
+### `vase.h`
+
+### `iterators/`
+
+#### `line.h`
+
+#### `petal.h`

README.md

@@ -56,9 +56,7 @@ It should support:
 - Error handling.
 - And more.
 
-Not done yet.
-
-### TODO immediately:
+### TODO:
 
 - Make "g" command work.
 - properly handle escapes for %q ' etc in ruby parser (rn everything is escapable.)

include/internal/vase/shard.h

@@ -24,9 +24,9 @@ struct Shard {
   static void retain(Shard *n);
   static void release(Shard *n);
 
-  static Shard *from_file(const std::filesystem::path &path, bool posix_ending);
-  static Shard *from_string(const char *data, uint64_t len, bool posix_ending);
-  static Shard *from_command(const char *cmd, bool posix_ending);
+  static Shard *from_file(const std::filesystem::path &path);
+  static Shard *from_string(const char *data, uint64_t len);
+  static Shard *from_command(const char *cmd);
 
   static std::pair<Shard *, Shard *> split(Shard *n, uint64_t offset);
   static Shard *concat(Shard *a, Shard *b);

src/internal/buffer/special/clip.cc

@@ -11,14 +11,14 @@ bool ClipBuffer::waste() {
 void ClipBuffer::saved_hook() {}
 
 uint64_t ClipBuffer::lines() {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   uint64_t lines = s ? s->lines + 1 : 0;
   vase::Shard::release(s);
   return lines;
 }
 
 uint64_t ClipBuffer::bytes() {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   uint64_t length = s ? s->length + 1 : 0;
   vase::Shard::release(s);
   return length;
@@ -57,7 +57,7 @@ void ClipBuffer::append(BEd &ctx, vase::Shard *text, uint64_t line) {
   ctx.prev().buffername = name;
   ctx.prev().start = line + 1;
   ctx.prev().end = line + (text ? text->lines + 1 : 0);
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   s = vase::insert(&ctx.append, s, text, line);
   clip_write(s);
   vase::Shard::release(s);
@@ -65,7 +65,7 @@ void ClipBuffer::append(BEd &ctx, vase::Shard *text, uint64_t line) {
 }
 
 void ClipBuffer::remove(BEd &ctx, uint64_t start_line, uint64_t end_line) {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   s = vase::erase(s, start_line, end_line);
   clip_write(s);
   ctx.prev().buffername = name;
@@ -85,7 +85,7 @@ void ClipBuffer::replace(BEd &ctx, vase::Shard *text, uint64_t start_line, uint6
   ctx.prev().end = start_line + text->lines;
   uint64_t new_count = text->lines + 1;
   uint64_t old_count = end_line - start_line + 1;
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   s = vase::replace(s, text, start_line, end_line);
   clip_write(s);
   vase::Shard::release(s);
@@ -99,7 +99,7 @@ void ClipBuffer::replace(BEd &ctx, vase::Shard *text, uint64_t start_line, uint6
 }
 
 void ClipBuffer::join(BEd &ctx, uint64_t start_line, uint64_t end_line) {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   s = vase::join(s, start_line, end_line);
   clip_write(s);
   vase::Shard::release(s);
@@ -116,7 +116,7 @@ void ClipBuffer::substitute(
   ctx.prev().buffername = name;
   ctx.prev().start = start_line;
   ctx.prev().end = end_line;
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   s = vase::substitute(
     &ctx.append,
     s,
@@ -138,21 +138,21 @@ void ClipBuffer::substitute(
 }
 
 vase::Shard *ClipBuffer::copy(uint64_t start_line, uint64_t end_line) {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   vase::Shard *o = vase::copy(s, start_line, end_line);
   vase::Shard::release(s);
   return o;
 }
 
 uint64_t ClipBuffer::find_next(std::string_view pattern, uint64_t start) {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   uint64_t line = vase::find_next(s, pattern, start);
   vase::Shard::release(s);
   return line;
 }
 
 uint64_t ClipBuffer::find_prev(std::string_view pattern, uint64_t start) {
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   uint64_t line = vase::find_prev(s, pattern, start);
   vase::Shard::release(s);
   return line;
@@ -176,7 +176,7 @@ void ClipBuffer::print(BEd &ctx, uint64_t start_line, uint64_t end_line) {
   ctx.prev().buffername = name;
   ctx.prev().start = start_line;
   ctx.prev().end = end_line;
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   vase::Iterator it(s, start_line - 1, Direction::Forward);
   while (it.next() && start_line++ <= end_line)
     ctx.io.write_line(it.line);
@@ -190,7 +190,7 @@ void ClipBuffer::number_print(BEd &ctx, uint64_t start_line, uint64_t end_line)
   uint8_t width = 1;
   for (uint64_t n = end_line; n >= 10; n /= 10)
     ++width;
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   vase::Iterator it(s, start_line - 1, Direction::Forward);
   while (it.next() && start_line <= end_line)
     ctx.io.write_line(std::format("{:>{}}\t{}", start_line++, width, it.line));
@@ -201,7 +201,7 @@ void ClipBuffer::list_print(BEd &ctx, uint64_t start_line, uint64_t end_line) {
   ctx.prev().buffername = name;
   ctx.prev().start = start_line;
   ctx.prev().end = end_line;
-  auto s = vase::Shard::from_command("xclip -selection clipboard -o", true);
+  auto s = vase::Shard::from_command("xclip -selection clipboard -o");
   vase::Iterator it(s, start_line - 1, Direction::Forward);
   while (it.next() && start_line++ <= end_line)
     ctx.io.write_line(list_string(it.line));

src/internal/functions/extended.cc

@@ -197,7 +197,7 @@ void Function::register_extented(BEd &ctx) {
         ctx.io.write("=> ", 3);
         auto parser = syntax::MiniParser(
           *ctx.languages["ruby"],
-          vase::Shard::from_string(line.data(), line.size(), true),
+          vase::Shard::from_string(line.data(), line.size()),
           nullptr
         );
         const auto &tokens = parser.lines[0].second;

src/internal/functions/posix.cc

@@ -144,17 +144,17 @@ void Function::register_posix(BEd &ctx) {
         vase::Shard *s = nullptr;
         if (std::holds_alternative<std::filesystem::path>(arg)) {
           auto path = std::get<std::filesystem::path>(arg);
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
           buf.set_filename(path);
         } else if (std::holds_alternative<ShellArg>(arg)) {
           auto cmd = std::get<ShellArg>(arg).cmd;
           ctx.escape_command(cmd, buf.filename().string());
-          s = vase::Shard::from_command(cmd.c_str(), true);
+          s = vase::Shard::from_command(cmd.c_str());
         } else {
           auto path = buf.filename();
           if (path.empty())
             throw ed_error("Need filename.");
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
         };
         try {
           buf.load(ctx, s);
@@ -190,17 +190,17 @@ void Function::register_posix(BEd &ctx) {
         vase::Shard *s = nullptr;
         if (std::holds_alternative<std::filesystem::path>(arg)) {
           auto path = std::get<std::filesystem::path>(arg);
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
           buf.set_filename(path);
         } else if (std::holds_alternative<ShellArg>(arg)) {
           auto cmd = std::get<ShellArg>(arg).cmd;
           ctx.escape_command(cmd, buf.filename().string());
-          s = vase::Shard::from_command(cmd.c_str(), true);
+          s = vase::Shard::from_command(cmd.c_str());
         } else {
           auto path = buf.filename();
           if (path.empty())
             throw ed_error("Need filename.");
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
         };
         try {
           buf.load(ctx, s);
@@ -588,18 +588,18 @@ void Function::register_posix(BEd &ctx) {
         vase::Shard *s = nullptr;
         if (std::holds_alternative<std::filesystem::path>(arg)) {
           auto path = std::get<std::filesystem::path>(arg);
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
           if (buf.filename().empty())
             buf.set_filename(path);
         } else if (std::holds_alternative<ShellArg>(arg)) {
           auto cmd = std::get<ShellArg>(arg).cmd;
           ctx.escape_command(cmd, buf.filename().string());
-          s = vase::Shard::from_command(cmd.c_str(), true);
+          s = vase::Shard::from_command(cmd.c_str());
         } else {
           auto path = buf.filename();
           if (path.empty())
             throw ed_error("Need filename.");
-          s = vase::Shard::from_file(path, true);
+          s = vase::Shard::from_file(path);
         };
         try {
           buf.append(ctx, s, addr.number);

src/internal/vase/shard.cc

@@ -202,7 +202,7 @@ Shard *Shard::build(Shard **pieces, uint64_t lo, uint64_t hi) {
   return node;
 }
 
-Shard *Shard::from_command(const char *cmd, bool posix_ending) {
+Shard *Shard::from_command(const char *cmd) {
   auto o = new OriginalStorage("/tmp");
   int dest_fd = o->fd;
   if (dest_fd == -1) {
@@ -278,23 +278,21 @@ Shard *Shard::from_command(const char *cmd, bool posix_ending) {
     io::IO::enable_raw();
     return nullptr;
   }
-  if (posix_ending) {
-    if (ending[1] == '\n') {
-      Petal *last = (Petal *)pieces.back();
-      last->lines--;
-      last->length--;
-      if (last->length == 0) {
-        Shard::release(last);
-        pieces.pop_back();
-        last = nullptr;
-        if (!pieces.empty())
-          last = (Petal *)pieces.back();
-        else
-          return nullptr;
-      }
-      if (last && ending[0] == '\r')
-        last->length--;
+  if (ending[1] == '\n') {
+    Petal *last = (Petal *)pieces.back();
+    last->lines--;
+    last->length--;
+    if (last->length == 0) {
+      Shard::release(last);
+      pieces.pop_back();
+      last = nullptr;
+      if (!pieces.empty())
+        last = (Petal *)pieces.back();
+      else
+        return nullptr;
     }
+    if (last && ending[0] == '\r')
+      last->length--;
   }
   o->initialize();
   io::IO::enable_raw();
@@ -303,7 +301,7 @@ Shard *Shard::from_command(const char *cmd, bool posix_ending) {
   return build(pieces.data(), 0, pieces.size());
 }
 
-Shard *Shard::from_file(const std::filesystem::path &path, bool posix_ending) {
+Shard *Shard::from_file(const std::filesystem::path &path) {
   auto o = new OriginalStorage("/tmp");
   int dest_fd = o->fd;
   if (dest_fd == -1) {
@@ -313,10 +311,10 @@ Shard *Shard::from_file(const std::filesystem::path &path, bool posix_ending) {
   int src_fd = open(path.c_str(), O_RDONLY);
   if (src_fd == -1) {
     delete o;
-    return nullptr;
+    throw ed_error("Couldn't open file.");
   }
   uint64_t total = std::filesystem::file_size(path);
-  if (posix_ending && total > 0) {
+  if (total > 0) {
     char last;
     if (pread(src_fd, &last, 1, (off_t)(total - 1)) != 1) {
       delete o;
@@ -381,7 +379,7 @@ Shard *Shard::from_file(const std::filesystem::path &path, bool posix_ending) {
   return build(pieces.data(), 0, pieces.size());
 }
 
-Shard *Shard::from_string(const char *data, uint64_t len, bool posix_ending) {
+Shard *Shard::from_string(const char *data, uint64_t len) {
   auto o = new OriginalStorage("/tmp");
   int dest_fd = o->fd;
   if (dest_fd == -1 || data == nullptr) {
@@ -389,7 +387,7 @@ Shard *Shard::from_string(const char *data, uint64_t len, bool posix_ending) {
     return nullptr;
   }
   uint64_t total = len;
-  if (posix_ending && total > 0) {
+  if (total > 0) {
     if (data[total - 1] == '\n') {
       total--;
       if (total > 0 && data[total - 1] == '\r')