1 files changed, 360 insertions, 0 deletions
diff --git a/kit/input_buffer.c b/kit/input_buffer.c
new file mode 100644
index 0000000..1f3e274
--- /dev/null
+++ b/kit/input_buffer.c
@@ -0,0 +1,360 @@
+#include "input_buffer.h"
+
+#include <assert.h>
+#include <string.h>
+
+enum { KIT_IB_CACHE_SIZE = 256 };
+
+static s32 kit_buf_adjust_(kit_input_buffer_t *buf, i64 size) {
+  assert(buf != NULL);
+  assert(size >= 0);
+
+  if (buf == NULL)
+    return KIT_ERROR_INTERNAL;
+
+  i64 offset = buf->data.size;
+
+  if (offset >= size)
+    return KIT_OK;
+
+  DA_RESIZE(buf->data, size);
+  if (buf->data.size != size)
+    return KIT_ERROR_OUT_OF_MEMORY;
+
+  str_t destination = { .size   = size - offset,
+                        .values = buf->data.values + offset };
+  i64   n           = IS_READ(buf->upstream, destination);
+
+  DA_RESIZE(buf->data, offset + n);
+  if (buf->data.size != offset + n)
+    return KIT_ERROR_OUT_OF_MEMORY;
+
+  return KIT_OK;
+}
+
+kit_input_buffer_t kit_ib_init(is_handle_t      upstream,
+                               kit_allocator_t *alloc) {
+  kit_input_buffer_t buf;
+  memset(&buf, 0, sizeof buf);
+
+  buf.upstream = upstream;
+  DA_INIT(buf.data, 0, alloc);
+
+  return buf;
+}
+
+void kit_ib_destroy(kit_input_buffer_t *buf) {
+  assert(buf != NULL);
+  if (buf == NULL)
+    return;
+
+  DA_DESTROY(buf->data);
+  memset(buf, 0, sizeof *buf);
+}
+
+kit_ib_token_t kit_ib_token(kit_input_buffer_t *buf) {
+  return (kit_ib_token_t) {
+    .status = KIT_OK, .offset = 0, .size = 0, .buffer = buf
+  };
+}
+
+kit_str_t kit_ib_str(kit_ib_token_t tok) {
+  assert(tok.buffer != NULL);
+
+  if (tok.buffer == NULL || tok.buffer->data.values == NULL)
+    return (str_t) { .size = 0, .values = NULL };
+
+  return (str_t) { .size   = tok.size,
+                   .values = tok.buffer->data.values + tok.offset };
+}
+
+kit_ib_token_t kit_ib_read(kit_ib_token_t tok, i64 size) {
+  assert(tok.buffer != NULL);
+
+  kit_ib_token_t next = tok;
+
+  next.offset = tok.offset + tok.size;
+  next.size   = 0;
+
+  if (tok.status != KIT_OK)
+    return next;
+
+  if (tok.buffer == NULL) {
+    next.status = KIT_ERROR_INVALID_ARGUMENT;
+    return next;
+  }
+
+  s32 s = kit_buf_adjust_(tok.buffer, tok.offset + tok.size + size);
+
+  if (s != KIT_OK) {
+    next.status = s;
+    return next;
+  }
+
+  assert(tok.buffer->data.values != NULL);
+
+  if (tok.buffer->data.values == NULL) {
+    next.status = KIT_ERROR_INTERNAL;
+    return next;
+  }
+
+  next.size = size < tok.buffer->data.size - tok.offset - tok.size
+                  ? size
+                  : tok.buffer->data.size - tok.offset - tok.size;
+
+  return next;
+}
+
+#define IB_CACHE_INIT_(res_)                                       \
+  str_builder_t cache_dynamic;                                     \
+  memset(&cache_dynamic, 0, sizeof cache_dynamic);                 \
+  char cache_static[KIT_IB_CACHE_SIZE];                            \
+                                                                   \
+  do {                                                             \
+    if (data.size > 0) {                                           \
+      if (data.size < KIT_IB_CACHE_SIZE) {                         \
+        memcpy(cache_static, data.values, data.size);              \
+        data.values = cache_static;                                \
+      } else {                                                     \
+        DA_INIT(cache_dynamic, data.size, tok.buffer->data.alloc); \
+        if (cache_dynamic.size != data.size) {                     \
+          (res_).status |= KIT_ERROR_OUT_OF_MEMORY;                \
+          return (res_);                                           \
+        }                                                          \
+        memcpy(cache_dynamic.values, data.values, data.size);      \
+        data.values = cache_dynamic.values;                        \
+      }                                                            \
+    }                                                              \
+  } while (0)
+
+#define IB_CACHE_CLEANUP_()           \
+  do {                                \
+    if (cache_dynamic.values != NULL) \
+      DA_DESTROY(cache_dynamic);      \
+  } while (0)
+
+kit_ib_token_t kit_ib_any(kit_ib_token_t tok, str_t data) {
+  assert(tok.buffer != NULL);
+
+  kit_ib_token_t next = tok;
+
+  next.offset = tok.offset + tok.size;
+  next.size   = 0;
+
+  if (tok.status != KIT_OK)
+    return next;
+
+  if (tok.buffer == NULL) {
+    next.status = KIT_ERROR_INVALID_ARGUMENT;
+    return next;
+  }
+
+  IB_CACHE_INIT_(next);
+
+  for (;; ++next.size) {
+    s32 s = kit_buf_adjust_(tok.buffer,
+                            tok.offset + tok.size + next.size + 1);
+
+    if (s != KIT_OK) {
+      next.status = s;
+      return next;
+    }
+
+    assert(tok.buffer->data.values != NULL);
+
+    if (tok.buffer->data.values == NULL) {
+      next.status = KIT_ERROR_INTERNAL;
+      return next;
+    }
+
+    if (tok.offset + tok.size + next.size >= tok.buffer->data.size)
+      break;
+
+    i8 found = 0;
+
+    for (i64 i = 0; i < data.size; i++)
+      if (data.values[i] ==
+          tok.buffer->data.values[next.offset + next.size]) {
+        found = 1;
+        break;
+      }
+
+    if (!found)
+      break;
+  }
+
+  IB_CACHE_CLEANUP_();
+
+  return next;
+}
+
+kit_ib_token_t kit_ib_none(kit_ib_token_t tok, str_t data) {
+  assert(tok.buffer != NULL);
+
+  kit_ib_token_t next = tok;
+
+  next.offset = tok.offset + tok.size;
+  next.size   = 0;
+
+  if (tok.status != KIT_OK)
+    return next;
+
+  if (tok.buffer == NULL) {
+    next.status = KIT_ERROR_INVALID_ARGUMENT;
+    return next;
+  }
+
+  IB_CACHE_INIT_(next);
+
+  for (;; ++next.size) {
+    s32 s = kit_buf_adjust_(tok.buffer,
+                            tok.offset + tok.size + next.size + 1);
+
+    if (s != KIT_OK) {
+      next.status = s;
+      return next;
+    }
+
+    assert(tok.buffer->data.values != NULL);
+
+    if (tok.buffer->data.values == NULL) {
+      next.status = KIT_ERROR_INTERNAL;
+      return next;
+    }
+
+    if (tok.offset + tok.size + next.size >= tok.buffer->data.size)
+      break;
+
+    i8 found = 0;
+
+    for (i64 i = 0; i < data.size; i++)
+      if (data.values[i] ==
+          tok.buffer->data.values[next.offset + next.size]) {
+        found = 1;
+        break;
+      }
+
+    if (found)
+      break;
+  }
+
+  IB_CACHE_CLEANUP_();
+
+  return next;
+}
+
+kit_ib_token_t kit_ib_exact(kit_ib_token_t tok, str_t data) {
+  kit_ib_token_t res = tok;
+
+  res.offset = tok.offset + tok.size;
+  res.size   = 0;
+
+  IB_CACHE_INIT_(res);
+
+  res = kit_ib_read(tok, data.size);
+  if (!AR_EQUAL(kit_ib_str(res), data))
+    res.status = KIT_PARSING_FAILED;
+
+  IB_CACHE_CLEANUP_();
+
+  return res;
+}
+
+kit_ib_token_t kit_ib_until(kit_ib_token_t tok, str_t data) {
+  assert(tok.buffer != NULL);
+
+  kit_ib_token_t next = tok;
+
+  next.offset = tok.offset + tok.size;
+  next.size   = 0;
+
+  if (tok.status != KIT_OK)
+    return next;
+
+  if (tok.buffer == NULL) {
+    next.status = KIT_ERROR_INVALID_ARGUMENT;
+    return next;
+  }
+
+  IB_CACHE_INIT_(next);
+
+  for (;; ++next.size) {
+    s32 s = kit_buf_adjust_(tok.buffer,
+                            tok.offset + tok.size + next.size + 1);
+
+    if (s != KIT_OK) {
+      next.status = s;
+      return next;
+    }
+
+    assert(tok.buffer->data.values != NULL);
+
+    if (tok.buffer->data.values == NULL) {
+      next.status = KIT_ERROR_INTERNAL;
+      return next;
+    }
+
+    if (tok.offset + tok.size + next.size >= tok.buffer->data.size)
+      break;
+
+    if (next.size + 1 >= data.size &&
+        AR_EQUAL(kit_str(data.size, tok.buffer->data.values +
+                                        (next.offset + next.size + 1 -
+                                         data.size)),
+                 data)) {
+      next.size -= data.size - 1;
+      break;
+    }
+  }
+
+  IB_CACHE_CLEANUP_();
+
+  return next;
+}
+
+kit_ib_token_t kit_ib_while(kit_ib_token_t           tok,
+                            kit_ib_read_condition_fn condition,
+                            void                    *context) {
+  assert(tok.buffer != NULL);
+
+  kit_ib_token_t next = tok;
+
+  next.offset = tok.offset + tok.size;
+  next.size   = 0;
+
+  if (tok.status != KIT_OK)
+    return next;
+
+  if (tok.buffer == NULL) {
+    next.status = KIT_ERROR_INVALID_ARGUMENT;
+    return next;
+  }
+
+  for (;; ++next.size) {
+    s32 s = kit_buf_adjust_(tok.buffer,
+                            tok.offset + tok.size + next.size + 1);
+
+    if (s != KIT_OK) {
+      next.status = s;
+      return next;
+    }
+
+    assert(tok.buffer->data.values != NULL);
+
+    if (tok.buffer->data.values == NULL) {
+      next.status = KIT_ERROR_INTERNAL;
+      return next;
+    }
+
+    if (tok.offset + tok.size + next.size >= tok.buffer->data.size)
+      break;
+
+    if (condition == NULL ||
+        !condition(kit_str(next.size + 1,
+                           tok.buffer->data.values + next.offset),
+                   context))
+      break;
+  }
+
+  return next;
+}